Communications method and apparatus

ABSTRACT

This application discloses example communications methods and apparatuses. One example method includes receiving a first request message from a terminal, where the first request message is used to request information used for PC5 interface-based communication of the terminal. A second request message can be sent to a policy and charging function network element based on the first request message, where the second request message is used to request the information used for the PC5 interface-based communication. A quality of service (QoS) rule used for the PC5 interface-based communication can then be received from the policy and charging function network element. The QoS rule can then be sent to the terminal based on the first request message, where the apparatus is a mobility management network element or located in a mobility management network element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/064,856, filed on Oct. 7, 2020, which is a continuation ofInternational Application No. PCT/CN2019/081975, filed on Apr. 9, 2019,which claims priority to Chinese Patent Application No. 201810313223.1,filed on Apr. 9, 2018. All of the afore-mentioned patent applicationsare hereby incorporated by reference in their entireties.

TECHNICAL FIELD

This application relates to the field of communications technologies,and in particular, to a communications method and apparatus.

BACKGROUND

Continuous development of mobile communications technologies brings lotsof innovative applications to various industries. For example, mobilebroadband, multimedia, machine type communication (MTC for short),industrial control, and an intelligent transportation system (ITS forshort) will become main use cases in the 5G era. Many applicationsrelate to a vehicle-to-everything (V2X for short) service, to bespecific, a vehicle may communicate with another device for transmissionof a V2X message, where the communication includes communication betweenvehicles, communication between a vehicle and a pedestrian,communication between a vehicle and a roadside unit, and the like. TheV2X message is sent over a PC5 interface between terminals. Currently,an application layer sets a ProSe per packet priority (PPPP for short)for each type of V2X message and transfers the PPPP to a communicationsnetwork layer (a non-access stratum (NAS for short) or an access stratum(AS for short)). To be specific, a mapping relationship between a V2Xmessage and a PPPP is configured on a terminal side, and the terminaland a base station perform negotiation, so that the base stationgenerates a mapping relationship between a PPPP and a PC5 interfaceresource for the terminal. When obtaining a PC5 interface resourcecorresponding to a V2X message to transmit the V2X message, the terminalsends, to the base station, a PPPP corresponding to the V2X message.Then, the base station determines the PC5 interface resource for the V2Xmessage based on the mapping relationship between a PPPP and a PC5interface resource, and sends the PC5 interface resource to theterminal, so that the terminal sends the V2X message based on the PC5interface resource. Setting of the PPPP reflects a quality of service(QoS for short) requirement of the V2X message.

A vehicle generates various types of V2X messages, for example, acooperative awareness message (CAM for short), a decentralizedenvironmental notification message (DENM for short), an entertainmentapplication message between vehicles, and navigation informationexchanged between vehicles. With development of a V2X technology, newtypes of V2X messages continuously emerge. For different upper-layerapplications, types of V2X messages generated by a vehicle usuallycorrespond to different QoS requirements. A terminal controls acorresponding PC5 interface resource by obtaining a QoS requirementcorresponding to a V2X message. However, because an existing mechanismis a mechanism in which the application layer sends QoS information to alower layer, the application layer may increase a QoS level withoutauthorization. In other words, QoS information that is of a V2X messageand that is obtained by the terminal is prone to be modified in anunauthorized manner. Consequently, the obtained QoS in formation isunreliable.

SUMMARY

Embodiments of the present invention provide a communications method andapparatus, to obtain, from a network side, QoS information used for PC5interface-based communication, thereby improving reliability of theobtained QoS information, and preventing the QoS information from beingmodified without authorization.

According to a first aspect, a communication method is provided. Thecommunication method includes: receiving, by a core network element, afirst request message from a terminal, where the first request messageis used to request information used for PC5 interface-basedcommunication of the terminal; and sending, by the core network elementto the terminal based on the first request message, a QoS rule (s) usedfor the PC5 interface-based communication. Optionally, the core networkelement may be a mobility management network element or a sessionmanagement function network element. That the first request message isused to request information used for PC5 interface-based communicationof the terminal may mean that the first request message may be used torequest the information used for the PC5 interface-based communicationof the terminal or that the first request message may be used to requestinformation used for V2X communication or other information, where theinformation used for the V2X communication or the other informationincludes the information for the PC5 interface-based communication ofthe terminal. In this way, QoS information used for the PC5interface-based communication can be obtained from a network side. Thishelps improve reliability and flexibility of the obtained QoSinformation, and prevents the QoS information from being modifiedwithout authorization.

With reference to the first aspect, in a first possible design of thefirst aspect, the core network element sends, to a base station based onthe first request message, a QoS profile used for the PC5interface-based communication.

With reference to the first aspect or the first possible design of thefirst aspect, in a second possible design of the first aspect, the corenetwork element may be the session management function network element.Further, the core network element such as the session managementfunction network element sends a second request message to a parameterconfiguration network element based on the first request message, wherethe second request message is used to request the information used forthe PC5 interface-based communication, or the second request message maybe used to request the information used for the V2X communication or theother information. The information used for the V2X communication or theother information includes the information for the PC5 interface-basedcommunication of the terminal. The core network element receives, fromthe parameter configuration network element, a policy and chargingcontrol (PCC for short) rule (s) used for the PC5 interface-basedcommunication. The core network element obtains the QoS rule and/or theQoS profile according to the PCC rule.

With reference to the first aspect or the first possible design of thefirst aspect, in a third possible design of the first aspect, the corenetwork element may be the mobility management network element. Further,the core network element such as the mobility management network elementsends a second request message to a parameter configuration networkelement based on the first request message, where the second requestmessage is used to request the information used for the PC5interface-based communication, or the second request message may be usedto request the information used for the V2X communication or the otherinformation. The information used for the V2X communication or the otherinformation includes the information for the PC5 interface-basedcommunication of the terminal. The core network element receives, fromthe parameter configuration network element, the QoS rule and/or the QoSprofile that are/is used for the PC5 interface-based communication. TheQoS rule and/or the QoS profile may be determined by the parameterconfiguration network element according to a PCC rule obtained based onthe second request message.

With reference to the first aspect, the first possible design of thefirst aspect, the second possible design of the first aspect, or thethird possible design of the first aspect, in a fourth possible designof the first aspect, the first request message includes first indicationinformation, where the first indication information is used to indicatethat the first request message is used to request the information usedfor the PC5 interface-based communication, or the first indicationinformation may be used to indicate that the first request message isused to request the information used for the V2X communication. Theinformation used for the V2X communication includes the information forthe PC5 interface-based communication. In this way, the core networkelement can quickly determine that the first request message is used torequest the information for the PC5 interface-based communication (orthe information for the V2X communication).

With reference to the second possible design of the first aspect or thethird possible design of the first aspect, in a fifth possible design ofthe first aspect, the second request message includes second indicationinformation, where the second indication information is used to indicatethat the second request message is used to request the information usedfor the PC5 interface-based communication, or the second indicationinformation may be used to indicate that the second request message isused to request the information used for the V2X communication. Theinformation used for the V2X communication includes the information forthe PC5 interface-based communication. In this way, the parameterconfiguration network element can quickly determine that the secondrequest message is used to request the information for the PC5interface-based communication (or the information for the V2Xcommunication).

With reference to the first possible design of the first aspect, in asixth possible design of the first aspect, the core network elementsends third indication information to the base station, where the thirdindication information is used to indicate that the QoS profile is usedfor the PC5 interface-based communication. In this way, the base stationcan quickly determine that the QoS profile is used for the PC5interface-based communication.

With reference to the second possible design of the first aspect, in aseventh possible design of the first aspect, the core network elementreceives fourth indication information from the parameter configurationnetwork element, where the fourth indication information is used toindicate that the PCC rule is used for the PC5 interface-basedcommunication. In this way, the core network element can quicklydetermine that the PCC rule is used for the PC5 interface-basedcommunication.

With reference to the third possible design of the first aspect, in aneighth possible design of the first aspect, the core network elementreceives fifth indication information from the parameter configurationnetwork element, where the fifth indication information is used toindicate that the QoS rule and/or the QoS profile are/is used for thePC5 interface-based communication. In this way, the core network elementcan quickly determine that the QoS rule and/or the QoS profile are/isused for the PC5 interface-based communication.

With reference to the first aspect, the first possible design of thefirst aspect, the second possible design of the first aspect, the thirdpossible design of the first aspect, the fourth possible design of thefirst aspect, the fifth possible design of the first aspect, the sixthpossible design of the first aspect, the seventh possible design of thefirst aspect, or the eighth possible design of the first aspect, in aninth possible design of the first aspect, the first request message isa protocol data unit (PDU for short) session establishment message or aPDU session modification message. In this case, the core network elementskips triggering establishment of an N3 tunnel and an N4 tunnel for aPDU session. In this way, system overheads can be reduced.

With reference to the fourth possible design of the first aspect, in atenth possible design of the first aspect, when the first requestmessage carries the first indication information, the core networkelement skips triggering establishment of an N3 tunnel and an N4 tunnel.In this way, system overheads can be reduced.

With reference to the ninth possible design of the first aspect, in aneleventh possible design of the first aspect, when there is no datatransmission on the PDU session, the core network element skipsinitiating a network release (AN release) procedure. In this way,reliability of the PC5 interface-based communication can be improved.

With reference to the ninth possible design of the first aspect, in atwelfth possible design of the first aspect, when there is no datatransmission on the PDU session, the core network element skipsinitiating a PDU session deactivation (selective deactivation of UPconnection of an existing PDU session) procedure. In this way,reliability of the PC5 interface-based communication can be improved.

With reference to the first aspect, the first possible design of thefirst aspect, the second possible design of the first aspect, the thirdpossible design of the first aspect, the fourth possible design of thefirst aspect, the fifth possible design of the first aspect, the sixthpossible design of the first aspect, the seventh possible design of thefirst aspect, the eighth possible design of the first aspect, the ninthpossible design of the first aspect, the tenth possible design of thefirst aspect, the eleventh possible design of the first aspect, or thetwelfth possible design of the first aspect, in a thirteenth possibledesign of the first aspect, the core network element may alternativelyreceive the PCC rule from the parameter configuration network element;the core network element obtains the QoS rule and/or the QoS profileaccording to the PCC rule; and the core network element sends the QoSrule to the terminal, and/or sends the QoS profile to the base station.Alternatively, the core network element receives the QoS rule and/or theQoS profile from the parameter configuration network element; and thecore network element sends the QoS rule to the terminal, and/or sendsthe QoS profile to the base station. Optionally, the core networkelement receives sixth indication information from the parameterconfiguration network element, where the sixth indication information isused to indicate that the PCC rule is used for the PC5 interface-basedcommunication, or the sixth indication information is used to indicatethat the QoS rule and/or the QoS profile are/is used for the PC5interface-based communication.

According to a second aspect, a communication method is provided. Thecommunication method includes: receiving, by a parameter configurationnetwork element, a first request message from a core network element,where the first request message is used to request information used forPC5 interface-based communication of a terminal; and sending, by theparameter configuration network element to the core network elementbased on the first request message, a policy and charging control PCCrule used for the PC5 interface-based communication; or sending, by theparameter configuration network element to the core network elementbased on the first request message, a quality of service QoS rule and/ora QoS profile that are/is used for the PC5 interface-basedcommunication. That the first request message is used to requestinformation used for PC5 interface-based communication of a terminal maymean that the first request message may be used to request theinformation used for the PC5 interface-based communication of theterminal or that the first request message may be used to requestinformation used for V2X communication or other information, where theinformation used for the V2X communication or the other informationincludes the information for the PC5 interface-based communication ofthe terminal. Optionally, the parameter configuration network elementmay be a policy and charging function PCF network element, and the firstrequest message is an access and mobility policy control create(Npcf_AMPolicyControl_Create) message. Alternatively, the parameterconfiguration network element may be a vehicle-to-everything V2Xparameter configuration network element, and the first request messageis a V2X parameter request message. Alternatively, the parameterconfiguration network element may be a session management functionnetwork element, and the first request message is a PDU session createsession management context request, such asNsmf_PDUSession_CreateSMContext Request message, which is provided by asession management function network element (such as SMF). In this way,QoS information used for the PC5 interface-based communication can beobtained from a network side. This helps improve reliability andflexibility of the obtained QoS information, and prevents the QoSinformation from being modified without authorization.

With reference to the second aspect, in a first possible design of thesecond aspect, the first request message includes first indicationinformation, where the first indication information is used to indicatethat the first request message is used to request the information usedfor the PC5 interface-based communication, or the first indicationinformation may be used to indicate that the first request message isused to request the information used for the V2X communication. Theinformation used for the V2X communication includes the information forthe PC5 interface-based communication. In this way, the parameterconfiguration network element can quickly determine that the firstrequest message is used to request the information for the PC5interface-based communication (or the information for the V2Xcommunication).

With reference to the second aspect or the first possible design of thesecond aspect, in a second possible design of the second aspect, theparameter configuration network element sends a second request messageto a PCF network element, where the second request message is used torequest, from the PCF network element, the information used for the PC5interface-based communication, or the second request message may be usedto request the information used for the V2X communication or the otherinformation. The information used for the V2X communication or the otherinformation includes the information for the PC5 interface-basedcommunication. The V2X parameter configuration network element receives,from the PCF network element, the PCC rule used for the PC5interface-based communication. Alternatively, the V2X parameterconfiguration network element receives, from the PCF network element,the QoS rule and/or the QoS profile that are/is used for the PC5interface-based communication.

With reference to the second possible design of the second aspect, in athird possible design of the second aspect, the second request messageincludes second indication information, where the second indicationinformation is used to indicate that the second request message is usedto request the information used for the PC5 interface-basedcommunication, or the second indication information may be used toindicate that the second request message is used to request theinformation used for the V2X communication. The information used for theV2X communication includes the information for the PC5 interface-basedcommunication. In this way, the PCF network element can quicklydetermine that the second request message is used to request theinformation for the PC5 interface-based communication (or theinformation for the V2X communication).

With reference to the second aspect, the first possible design of thesecond aspect, the second possible design of the second aspect, or thethird possible design of the second aspect, in a fourth possible designof the second aspect, the parameter configuration network element sendsthird indication information to the core network element, where thethird indication information is used to indicate that the PCC rule isused for the PC5 interface-based communication, or is used to indicatethat the QoS rule and/or the QoS profile are/is used for the PC5interface-based communication. In this way, the core network element canquickly determine that the PCC rule, or the QoS rule and/or the QoSprofile are/is used for the PC5 interface-based communication (or theinformation for the V2X communication).

With reference to the second aspect, the first possible design of thesecond aspect, the second possible design of the second aspect, thethird possible design of the second aspect, or the fourth possibledesign of the second aspect, in a fifth possible design of the secondaspect, the parameter configuration network element obtains the PCC ruleused for the PC5 interface-based communication of the terminal, and theparameter configuration network element sends the PCC rule to the corenetwork element. Alternatively, the parameter configuration networkelement obtains the QoS rule and/or the QoS profile that are/is used forthe PC5 interface-based communication of the terminal; and the parameterconfiguration network element sends the QoS rule and/or the QoS profileto the core network element. The parameter configuration network elementsends fourth indication information to the core network element, wherethe fourth indication information is used to indicate that the PCC ruleis used for the PC5 interface-based communication, or the fourthindication information is used to indicate that the QoS rule and/or theQoS profile are/is used for the PC5 interface-based communication.

According to a third aspect, a communication method is provided. Thecommunication method includes: receiving, by a base station, a requestmessage from a terminal, where the request message is used to requestinformation used for PC5 interface-based communication of the terminal;sending, by the base station, the request message to a core networkelement; and receiving, by the base station from the core networkelement, a quality of service QoS rule used for the PC5 interface-basedcommunication, and sending the QoS rule to the terminal. That therequest message is used to request information used for PC5interface-based communication of the terminal may mean that the requestmessage may be used to request the information used for the PC5interface-based communication of the terminal or that the requestmessage may be used to request information used for V2X communication orother information, where the information used for the V2X communicationor the other information includes the information for the PC5interface-based communication of the terminal. In this way, QoSinformation used for the PC5 interface-based communication can beobtained from a network side. This helps improve reliability andflexibility of the obtained QoS information, and prevents the QoSinformation from being modified without authorization.

With reference to the third aspect, in a first possible design of thethird aspect, the base station receives, from the core network element,a QoS profile used for the PC5 interface-based communication.

With reference to the third aspect or the first possible design of thethird aspect, in a second possible design of the third aspect, therequest message includes first indication information, where the firstindication information is used to indicate that the request message isused to request the information used for the PC5 interface-basedcommunication, or the first indication information may be used toindicate that the request message is used to request the informationused for the V2X communication. The information used for the V2Xcommunication includes the information for the PC5 interface-basedcommunication.

With reference to the first possible design of the third aspect or thesecond possible design of the third aspect, in a third possible designof the third aspect, the base station receives second indicationinformation from the core network element, where the second indicationinformation is used to indicate that the QoS profile is used for the PC5interface-based communication. In this way, the core network elementquickly determines the QoS profile for the PC5 interface-basedcommunication (or the information for the V2X communication).

With reference to the third aspect, the first possible design of thethird aspect, the second possible design of the third aspect, or thethird possible design of the third aspect, in a fourth possible designof the third aspect, the request message is a PDU session establishmentmessage or a PDU session modification message, and the base stationskips triggering establishment of an air-interface data radio bearer(data radio bearer, DRB for short) and/or an N3 tunnel for a PDUsession. For example, the base station skips triggering theestablishment of the N3 tunnel and the air-interface DRB for the PDUsession. For another example, the base station skips triggering theestablishment of the N3 tunnel for the PDU session, but may establishthe air-interface DRB, to reuse an existing scheduling mechanism andreduce complexity of air-interface resource scheduling.

With reference to the second possible design of the third aspect, in afifth possible design of the third aspect, when the request messagecarries the first indication information, the base station skipstriggering establishment of a DRB and/or an N3 tunnel.

With reference to the third aspect, the first possible design of thethird aspect, the second possible design of the third aspect, the thirdpossible design of the third aspect, the fourth possible design of thethird aspect, or the fifth possible design of the third aspect, in asixth possible design of the third aspect, the base station receives ascheduling request from the terminal, where the scheduling requestincludes an identifier of the QoS rule; and the base station sendsscheduled-resource information to the terminal based on the identifierof the QoS rule. The scheduled-resource information is information abouta resource used for the PC5 interface-based communication.

With reference to the third aspect, the first possible design of thethird aspect, the second possible design of the third aspect, the thirdpossible design of the third aspect, the fourth possible design of thethird aspect, the fifth possible design of the third aspect, or thesixth possible design of the third aspect, in a seventh possible designof the third aspect, the base station receives the QoS profile and/orthe QoS rule from the core network element; and if receiving the QoSrule, the base station sends the QoS rule to the terminal. Optionally,the base station may further receive third indication information fromthe core network element, where the third indication information is usedto indicate that the QoS profile and/or the QoS rule are/is used for thePC5 interface-based communication. Further optionally, the base stationmay send the third indication information to the terminal, where thethird indication information is used to indicate that the QoS rule isused for the PC5 interface-based communication.

According to a fourth aspect, a communication method is provided. Thecommunication method includes: sending, by a terminal, a request messageto a core network element, where the request message is used to requestinformation used for PC5 interface-based communication of the terminal;and receiving, by the terminal from the core network element, a qualityof service QoS rule used for the PC5 interface-based communication. Thatthe request message is used to request information used for PC5interface-based communication of the terminal may mean that the requestmessage may be used to request the information used for the PC5interface-based communication of the terminal or that the requestmessage may be used to request information used for V2X communication orother information, where the information used for the V2X communicationor the other information includes the information for the PC5interface-based communication of the terminal. In this way, QoSinformation used for the PC5 interface-based communication can beobtained from a network side. This helps improve reliability andflexibility of the obtained QoS information, and prevents the QoSinformation from being modified without authorization.

With reference to the fourth aspect, in a first possible design of thefourth aspect, the request message includes first indicationinformation, where the first indication information is used to indicatethat the request message is used to request the information used for thePC5 interface-based communication, or the first indication informationmay be used to indicate that the request message is used to request theinformation used for the V2X communication. The information used for theV2X communication includes the information for the PC5 interface-basedcommunication. In this way, the core network element can quicklydetermine that the request message is used to request the informationfor the PC5 interface-based communication (or the information for theV2X communication).

With reference to the fourth aspect or the first possible design of thefourth aspect, in a second possible design of the fourth aspect, theterminal may further receive second indication information from the corenetwork element, where the second indication information is used toindicate that the QoS rule is used for the PC5 interface-basedcommunication.

With reference to the fourth aspect, the first possible design of thefourth aspect, or the second possible design of the fourth aspect, in athird possible design of the fourth aspect, the terminal sends ascheduling request to a base station, where the scheduling requestincludes an identifier of the QoS rule; and the terminal receivesscheduled-resource information from the base station, and sends a V2Xmessage on a resource corresponding to the scheduled-resourceinformation. In this way, the terminal can obtain, from the base stationaccording to the QoS rule, PC5 interface resource information used toperform a V2X service. The scheduled-resource information is informationabout the resource used for the PC5 interface-based communication.

With reference to the fourth aspect, the first possible design of thefourth aspect, or the second possible design of the fourth aspect, in afourth possible design of the fourth aspect, the terminal obtains QoSrequirement information of a V2X message according to the QoS rule; andthe terminal determines scheduled-resource information based on the QoSrequirement information, and sends the V2X message on a resourcecorresponding to the scheduled-resource information. Thescheduled-resource information is information about the resource usedfor the PC5 interface-based communication. In this way, afterdetermining a QoS requirement according to the QoS rule, the terminalcan obtain, based on the QoS requirement, PC5 interface resourceinformation used to perform a V2X service.

With reference to the fourth aspect, the first possible design of thefourth aspect, the second possible design of the fourth aspect, thethird possible design of the fourth aspect, or the fourth possibledesign of the fourth aspect, in a fifth possible design of the fourthaspect, the terminal receives the QoS rule from the core networkelement. Optionally, the terminal may further receive third indicationinformation from the core network element, where the third indicationinformation is used to indicate that the QoS rule is used for the PC5interface-based communication.

According to a fifth aspect, a communication method is provided. Thecommunication method includes: receiving, by a core network element, aPCC rule from a parameter configuration network element; obtaining, bythe core network element, a quality of service QoS rule and/or a QoSprofile according to the PCC rule; and sending, by the core networkelement, the QoS rule to a terminal, and/or sending the QoS profile to abase station, where optionally, the core network element may furtherreceive indication information from the parameter configuration networkelement, where the indication information is used to indicate that thePCC rule is used for PC5 interface-based communication; or receiving, bya core network element, a QoS rule and/or a QoS profile from a parameterconfiguration network element; and sending, by the core network element,the QoS rule to a terminal, and/or sending the QoS profile to a basestation, where optionally, the core network element receives indicationinformation from the parameter configuration network element, where theindication information is used to indicate that the QoS rule and/or theQoS profile are/is used for PC5 interface-based communication.

Optionally, the core network element may further perform some or allsteps of the core network element according to the first aspect. Detailsare not described herein again.

According to a sixth aspect, a communication method is provided. Thecommunication method includes: obtaining, by a parameter configurationnetwork element, a PCC rule used for PC5 interface-based communicationof a terminal; and sending, by the parameter configuration networkelement, the PCC rule to a core network element, where optionally, theparameter configuration network element sends indication information tothe core network element, where the indication information is used toindicate that the PCC rule is used for the PC5 interface-basedcommunication; or obtaining, by a parameter configuration networkelement, a QoS rule and/or a QoS profile that are/is used for PC5interface-based communication of a terminal; and sending, by theparameter configuration network element, the QoS rule and/or the QoSprofile to a core network element, where optionally, the parameterconfiguration network element sends indication information to the corenetwork element, where the indication information is used to indicatethat the QoS rule and/or the QoS profile are/is used for the PC5interface-based communication.

Optionally, the parameter configuration network element may furtherperform some or all steps of the parameter configuration network elementaccording to the second aspect. Details are not described herein again.

According to a seventh aspect, a communication method is provided. Thecommunication method includes: receiving, by a base station, a QoSprofile and/or a QoS rule from a core network element; and if receivingthe QoS rule, sending, by the base station, the QoS rule to a terminal.Optionally, the base station may further receive indication informationfrom the core network element, where the indication information is usedto indicate that the QoS profile and/or the QoS rule are/is used for PC5interface-based communication. Further optionally, the base station mayfurther send the indication information to the terminal, to indicatethat the QoS rule is used for the PC5 interface-based communication.

Optionally, the base station may further perform some or all steps ofthe base station according to the third aspect. Details are notdescribed herein again.

According to an eighth aspect, a communication method is provided. Thecommunication method includes: receiving, by a terminal, a QoS rule froma core network element. Optionally, the terminal may further receiveindication information from the core network element, where theindication information is used to indicate that the QoS rule is used forPC5 interface-based communication.

Optionally, the terminal may further perform some or all steps of theterminal according to the fourth aspect. Details are not describedherein again.

According to a ninth aspect, a communications apparatus is provided. Thecommunications apparatus includes units or means configured to performthe steps in the method according to the first aspect and/or the fifthaspect. The communications apparatus may be a core network element suchas a mobility management network element or a session managementfunction network element, or may be at least one processing element orchip.

According to a tenth aspect, a communications apparatus is provided. Thecommunications apparatus includes a transceiver, a memory, and aprocessor. The processor is coupled to the memory and the transceiver.The memory is configured to store a program. The processor invokes theprogram stored in the memory, to perform the method according to thefirst aspect and/or the fifth aspect. The transceiver is configured toreceive and/or send information. The communications apparatus may be acore network element such as a mobility management network element or asession management function network element, or may be at least oneprocessing element or chip.

According to an eleventh aspect, a communications apparatus is provided.The communications apparatus includes units or means configured toperform the steps in the method according to the second aspect and/orthe sixth aspect. The communications apparatus may be a parameterconfiguration network element, or may be at least one processing elementor chip.

According to a twelfth aspect, a communications apparatus is provided.The communications apparatus includes a transceiver, a memory, and aprocessor. The processor is coupled to the memory and the transceiver.The memory is configured to store a program. The processor invokes theprogram stored in the memory, to perform the method according to thesecond aspect and/or the sixth aspect. The transceiver is configured toreceive and/or send information. The communications apparatus may be aparameter configuration network element, or may be at least oneprocessing element or chip.

According to a thirteenth aspect, a communications apparatus isprovided. The communications apparatus includes units or meansconfigured to perform the steps in the method according to the thirdaspect and/or the seventh aspect. The communications apparatus may be abase station, or may be at least one processing element or chip.

According to a fourteenth aspect, a communications apparatus isprovided. The communications apparatus includes a transceiver, a memory,and a processor. The processor is coupled to the memory and thetransceiver. The memory is configured to store a program. The processorinvokes the program stored in the memory, to perform the methodaccording to the third aspect and/or the seventh aspect. The transceiveris configured to receive and/or send information. The communicationsapparatus may be a base station, or may be at least one processingelement or chip.

According to a fifteenth aspect, a communications apparatus is provided.The communications apparatus includes units or means configured toperform the steps in the method according to the fourth aspect and/orthe eighth aspect. The communications apparatus may be a terminal, ormay be at least one processing element or chip.

According to a sixteenth aspect, a communications apparatus is provided.The communications apparatus includes a transceiver, a memory, and aprocessor. The processor is coupled to the memory and the transceiver.The memory is configured to store a program. The processor invokes theprogram stored in the memory, to perform the method according to thefourth aspect and/or the eighth aspect. The transceiver is configured toreceive and/or send information. The communications apparatus may be aterminal, or may be at least one processing element or chip.

According to a seventeenth aspect, a communications system is provided.The system includes the core network element, the parameterconfiguration network element, the base station, and/or the terminalaccording to the foregoing aspects.

In another possible design, the system further includes another devicethat interacts with the core network element, the parameterconfiguration network element, the base station, and/or the terminal inthe solutions provided in the embodiments of the present invention.

According to an eighteenth aspect, a computer storage medium isprovided. The computer storage medium is configured to store a computersoftware instruction used by the foregoing communications apparatus, andthe computer software instruction includes a program designed forexecuting the foregoing aspects.

According to a nineteenth aspect, a computer program product includingan instruction is further provided. When the computer program product isrun on a computer, the computer is enabled to perform the methodaccording to the foregoing aspects.

According to a twentieth aspect, a chip system is provided. The chipsystem includes a processor, used by a communications apparatus toimplement functions in the foregoing aspects, for example, obtain orprocess data and/or information in the foregoing method. In a possibledesign, the chip system further includes a memory, and the memory isconfigured to store a program instruction and data that are necessaryfor the communications apparatus. The chip system may include a chip, ormay include a chip and another discrete component.

In the solutions provided in the embodiments of the present invention,the terminal may send, to the core network element, the request messageused to request the information used for the PC5 interface-basedcommunication of the terminal, so that the core network element cansend, to the terminal based on the request message, the QoS rule usedfor the PC5 interface-based communication. In this way, the QoSinformation used for the PC5 interface-based communication can beobtained from the network side. This helps improve the reliability andflexibility of the obtained QoS information, and prevents the QoSinformation from being modified without authorization.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention or in the background more clearly, the following describes theaccompanying drawings in the embodiments of the present invention or thebackground.

FIG. 1 is a schematic diagram of a communications system;

FIG. 2 a is a schematic interaction diagram of a communication methodaccording to an embodiment of the present invention;

FIG. 2 b is a schematic interaction diagram of another communicationmethod according to an embodiment of the present invention;

FIG. 3 is a schematic interaction diagram of still another communicationmethod according to an embodiment of the present invention;

FIG. 4 is a schematic interaction diagram of still another communicationmethod according to an embodiment of the present invention;

FIG. 5 is a schematic interaction diagram of still another communicationmethod according to an embodiment of the present invention;

FIG. 6 is a schematic interaction diagram of still another communicationmethod according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of another communications system;

FIG. 8 a -1 and FIG. 8 a -2 are a schematic interaction diagram of stillanother communication method according to an embodiment of the presentinvention;

FIG. 8 b -1 and FIG. 8 b -2 are a schematic interaction diagram of stillanother communication method according to an embodiment of the presentinvention;

FIG. 9 is a schematic interaction diagram of still another communicationmethod according to an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a communications apparatusaccording to an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of another communicationsapparatus according to an embodiment of the present invention;

FIG. 12 is a schematic structural diagram of still anothercommunications apparatus according to an embodiment of the presentinvention;

FIG. 13 is a schematic structural diagram of still anothercommunications apparatus according to an embodiment of the presentinvention;

FIG. 14 is a schematic structural diagram of still anothercommunications apparatus according to an embodiment of the presentinvention;

FIG. 15 is a schematic structural diagram of still anothercommunications apparatus according to an embodiment of the presentinvention;

FIG. 16 is a schematic structural diagram of still anothercommunications apparatus according to an embodiment of the presentinvention; and

FIG. 17 is a schematic structural diagram of still anothercommunications apparatus according to an embodiment of the presentinvention.

DESCRIPTION OF EMBODIMENTS

The technical solutions of this application may be applied to variouscommunications systems, for example, a universal mobiletelecommunications system (UMTS for short) and a long term evolution(LTE for short) network. With continuous development of communicationstechnologies, the technical solutions of this application may further beapplied to a future network, for example, a 5G network that may also bereferred to as a new radio (NR for short) network, or may be applied toa D2D (device to device) network, an M2M (machine to machine) network,or the like.

FIG. 1 is a schematic diagram of a communications system according tothis application. As shown in FIG. 1 , the communications system mayinclude a terminal, a base station, a core network element, and aparameter configuration network element. The terminal, the base station,the core network element, and the parameter configuration networkelement may communicate with each other through the foregoingcommunications systems such as an LTE system or a 5G system, forexample, to obtain information used for PC5 interface-basedcommunication, thereby implementing transmission of a V2X message basedon the PC5 interface-based communication. The V2X communication includesvehicle-to-vehicle V2V communication, vehicle-to-pedestrian V2Pcommunication, vehicle-to-roadside-unit V21 communication, and the like.A PC5 interface is a communications interface between terminals, and thePC5 interface-based communication is communication between theterminals.

The terminal is a device having a communication function, and mayinclude a handheld device having a wireless communication function, avehicle-mounted device, a wearable device, a computing device, anotherprocessing device connected to a wireless modem, or the like. Theterminal may have different names in different networks, for example, aterminal, user equipment (UE for short), a mobile station, a subscriberunit, a station, a cellular phone, a personal digital assistant, awireless modem, a wireless communications device, a handheld device, alaptop computer, a cordless phone, and a wireless local loop station.The terminal may be a wireless terminal or a wired terminal. Thewireless terminal may be a device that provides a user with voice and/ordata connectivity, the handheld device having a wireless connectionfunction, or the another processing device connected to the wirelessmodem. The wireless terminal may communicate with one or more corenetworks through a radio access network (RAN).

The core network element may be a network element that requests, for theterminal, information used for PC5 interface-based communication, andincludes a mobility management network element or a session managementfunction network element. For example, the core network element may bespecifically an access and mobility management function (AMF for short)entity, a session management function (SMF for short) entity, a mobilitymanagement entity (MME for short), a serving gateway (S-GW for short),or a packet data network gateway (P-GW for short). The parameterconfiguration network element may be a network element that obtains theinformation used for the PC5 interface-based communication, for example,may be a network element that allocates, to the terminal, theinformation used for the PC5 interface-based communication. For example,the parameter configuration network element may be a policy and chargingfunction (PCF for short) entity, a policy and charging rules function(PCRF for short) entity, a V2X parameter configuration network elementsuch as a V2X control function, or a session management network elementsuch as an SMF. Examples are not listed one by one herein.

This application discloses a communications method and apparatus, toobtain, from a network side, QoS information used for PC5interface-based communication, thereby improving reliability of theobtained QoS information, and preventing the QoS information from beingmodified without authorization. Details are separately described below.

FIG. 2 a is a schematic interaction diagram of a communication methodaccording to an embodiment of the present invention. As shown in FIG. 2a , the method may include the following steps.

201. A terminal sends a first request message to a core network element,where the first request message is used to request information used forPC5 interface-based communication of the terminal.

For example, the terminal may send the first request message to a basestation, and then the base station may forward the first request messageto the core network element. In other words, the terminal may send thefirst request message to the core network element through the basestation.

The core network element may be a mobility management network element ora session management function network element.

In a replaceable scenario, the first request message is used to requestinformation used for V2X communication or communication information,where the information used for the V2X communication or thecommunication information includes the information for the PC5interface-based communication of the terminal.

The first request message may be a message such as a registrationrequest (for example, may include (a registration type, a UE identity(such as a subscription concealed identifier (SUCI) or a 5G globallyunique temporary identity (5G-GUTI)), a UE 5GC capability UE 5GCcapability, or a PDU session status PDU session status)); a servicerequest (for example, may include a list of PDU sessions to be activatedlist of PDU sessions to be activated or a PDU session status PDU sessionstatus, where in this scenario, the terminal may first send a UEidentity to the base station, and then the base station sends the UEidentity and the service request to an AMF together); a PDU sessionestablishment request (for example, may include a PDU session identifierPDU session ID or a requested PDU type requested PDU type, where in thisscenario, an AMF may send a UE identity (for example, a subscriptionpermanent identifier (SUPI)) and the PDU session establishment requestto an SMF together); a PDU session modification request (for example,may include a PDU session ID or an operation type operation); or a NASmessage (for example, may include single network slice selectionassistance information (S-NSSAI), a data network name (DNN), a PDUsession ID, or a PDU session establishment request PDU sessionestablishment request); or may be a newly added message (new message forshort). This is not limited in this application.

Further optionally, the first request message further includes (carries)first indication information, where the first indication information maybe used to indicate that the first request message is used to requestthe information used for the PC5 interface-based communication.

It is clear that in the foregoing replaceable scenario, the firstindication information may be used to indicate that the first requestmessage is used to request the information used for the V2Xcommunication or a communication parameter used for the V2Xcommunication, and the information used for the V2X communication or thecommunication parameter includes the information for the PC5interface-based communication of the terminal.

The information used for the PC5 interface-based communication of theterminal may include information such as a PCC rule (s), a QoS rule, ora QoS profile.

202. The core network element sends, to the terminal based on the firstrequest message, the QoS rule used for the PC5 interface-basedcommunication.

For example, the core network element receives the first request messagefrom the terminal through the base station, obtains, based on the firstrequest message, the QoS rule (s) used for the PC5 interface-basedcommunication of the terminal, and sends the QoS rule to the terminalthrough the base station.

The QoS rule used for the PC5 interface-based communication of theterminal may be obtained based on the first request message in aplurality of implementations, as described below.

Manner 1: The core network element obtains, based on the first requestmessage, the QoS rule from information stored in the core networkelement.

For example, the core network element stores the information used forthe PC5 interface-based communication of the terminal, where theinformation for the PC5 interface-based communication includes the QoSrule. In this way, the core network element can obtain, after receivingthe first request message, the QoS rule from the stored information.

Manner 2: The core network element obtains the QoS rule from unifieddata management (UDM for short) based on the first request message.

For example, the core network element obtains subscription informationof the terminal from the UDM (where the UDM obtains the subscriptioninformation of the terminal from a unified data repository (UDR forshort)), where the subscription information includes the QoS rule, sothat the core network element obtains the QoS rule from the subscriptioninformation. Specifically, the first request message may carry anidentifier of the terminal, so that the core network element can obtainthe QoS rule from the subscription information based on the identifierof the terminal.

Manner 3: The core network element obtains the QoS rule from a parameterconfiguration network element based on the first request message.

For Manner 3, refer to related descriptions of the third or the fourthimplementation scenario in the embodiment shown in FIG. 2 a . Detailsare not described again.

In this embodiment of the present invention, the terminal may send, tothe core network element, the request message used to request theinformation used for the PC5 interface-based communication of theterminal, so that the core network element can send, to the terminalbased on the request message, the QoS rule used for the PC5interface-based communication. In this way, QoS information used for thePC5 interface-based communication can be obtained from a network side.This helps improve reliability and flexibility of the obtained QoSinformation, and prevents the QoS information from being modifiedwithout authorization.

Optionally, in the first implementation scenario of the foregoingmethod, the method further includes: sending, by the core networkelement to the base station based on the first request message, the QoSprofile used for the PC5 interface-based communication.

The QoS profile is used by the base station to perform QoS processingfor the PC5 interface-based communication. The QoS profile may bereferred to as a QoS profile, a QoS attribute, a QoS configuration file,a QoS context, or the like. This is not limited in this application.

For example, the core network element receives the first request messagefrom the terminal through the base station, obtains, based on the firstrequest message, the QoS profile used for the PC5 interface-basedcommunication, and sends the QoS profile to the base station.

Correspondingly, the base station may receive, from the core networkelement, the QoS profile used for the PC5 interface-based communication,and then may negotiate with the terminal by using RRC signaling, to binda QoS flow (for example, a QoS flow of a PDU session or a PDU session)on a PC5 interface to a corresponding PC5 interface resource.

The following manners may be used by the core network element to obtain,based on the first request message, the QoS profile used for the PC5interface-based communication.

Manner 1: The core network element obtains, based on the first requestmessage, the QoS profile from the information stored in the core networkelement.

Manner 2: The core network element obtains the QoS profile from the UDMbased on the first request message.

Manner 3: The core network element obtains the QoS profile from theparameter configuration network element based on the first requestmessage.

For Manner 1 to Manner 3, refer to the related descriptions of Manner 1to Manner 3 in step 202. To be specific, the QoS rule in the relateddescriptions of Manner 1 to Manner 3 in step 202 is replaced with theQoS profile. Details are not described again.

Optionally, in the second implementation scenario of the foregoingmethod, the method further includes:

obtaining, by the terminal, scheduled-resource information according tothe QoS rule, and sending a V2X message on a resource corresponding tothe scheduled-resource information.

The scheduled-resource information may be requested by the terminal fromthe base station, or may be determined by the terminal according to theQoS rule. Further optionally, the QoS profile may include one or more ofinformation such as a 5G QoS identifier (5QI), an allocation andretention priority (ARP), a reflective QoS attribute (RQA), a guaranteedflow bit rate (GFBR), a maximum flow bit rate (MFBR), a correspondencebetween a data packet processing priority and a PPPP, a correspondencebetween a data packet delay requirement and a PPPP, and a correspondencebetween a data packet loss rate and ProSe per-packet reliability (PPPRfor short). The QoS rule may include: one or more of information such asa QoS rule identifier, a QoS flow identifier (QFI), a packet filter setin an SDF template, the 5QI, a guaranteed bit rate (GBR), a maximum bitrate (MBR), a correspondence between an application identifier and aPPPP, the correspondence between a data packet processing priority and aPPPP, the correspondence between a data packet delay requirement and aPPPP, and the correspondence between a data packet loss rate and a PPPR.Usually, the QoS profile does not include the QFI.

For example, the V2X message of the terminal is classified into acorresponding QoS flow of a PDU session by using the SDF template in theQoS rule. The terminal may send a scheduling request to the basestation, where the scheduling request includes an identifier of the QoSrule, and the identifier of the QoS rule may include the QoS ruleidentifier, the 5QI, or an identifier of the QoS flow of the PDU session(for example, the QoS flow ID, or the PDU session ID and the QoS flowID). The base station receives the scheduling request from the terminal,and may determine the scheduled-resource information for the terminalbased on the identifier of the QoS rule, for example, determinecorresponding QoS requirement information for the terminal based on theidentifier of the QoS rule and the QoS profile (where for example, amapping relationship is preconfigured between the identifier of the QoSrule and QoS profile information, so that the base station can determinea QoS requirement based on the QoS profile information). Further, thebase station allocates a scheduled resource to the terminal based on theQoS requirement information, and sends, to the terminal, informationabout the scheduled resource, namely, the scheduled-resourceinformation. The terminal may receive the scheduled-resource informationfrom the base station, and send the V2X message on the resourcecorresponding to the scheduled-resource information.

For another example, the terminal and the base station establish amapping relationship between the QoS flow of the PDU session and alogical channel group identity (LCGID for short) by using radio resourcecontrol (RRC for short) signaling based on the QoS rule and the QoSprofile (where the terminal and the base station both have the mappingrelationship). Further, the terminal may send a scheduling request tothe base station, where the scheduling request includes the LCGID.Further, the base station allocates a corresponding PC5 interfaceresource, namely, a scheduled resource, to the terminal based on theLCGID, and sends information about the scheduled resource to theterminal. The terminal may receive the scheduled-resource informationfrom the base station, and send the V2X message on the resourcecorresponding to the scheduled-resource information.

For still another example, based on the QoS rule and the QoS profile,the terminal may establish a mapping relationship between the QoS ruleand a PPPP, and the base station may establish a mapping relationshipbetween the QoS profile and the PPPP. In this case, the terminal maysend a scheduling request to the base station, where the schedulingrequest includes an identifier of the QoS rule, and the identifier ofthe QoS rule may include PPPP information. Further, the base station maydetermine corresponding QoS profile information based on the PPPP,allocates a corresponding PC5 interface resource, namely, a scheduledresource, to the terminal based on the corresponding QoS profileinformation, and sends information about the scheduled resource to theterminal. The terminal may receive the scheduled-resource informationfrom the base station, and send the V2X message on the resourcecorresponding to the scheduled-resource information.

It should be understood that the QoS rule used for the PC5interface-based communication and a QoS rule used for a Uu interface mayinclude different information. For example, the QoS rule used for thePC5 interface-based communication may include the packet filter set inthe SDF template, the 5QI, or the correspondence between an applicationidentifier and a PPPP, and optionally, may further include thecorrespondence between a data packet processing priority and a PPPP, thecorrespondence between a data packet delay requirement and a PPPP, thecorrespondence between a data packet loss rate and a PPPR, or the like.The QoS profile used for the PC5 interface-based communication mayinclude only the 5QI or the ARP, or may include the correspondencebetween a data packet processing priority and a PPPP, the correspondencebetween a data packet delay requirement and a PPPP, the correspondencebetween a data packet loss rate and a PPPR, or the like. In a futurenetwork, the PCC rule, the QoS rule, and/or the QoS profile mayalternatively have other names. This is not limited in this application.

For another example, the terminal may obtain QoS requirement informationof the V2X message according to the QoS rule, and determine thescheduled-resource information based on the QoS requirement information,to send the V2X message on the resource corresponding to thescheduled-resource information.

Optionally, in the third implementation scenario of the foregoingembodiment, the core network element is the session management functionnetwork element, and the method further includes:

sending, by the session management function network element, a secondrequest message to the parameter configuration network element based onthe first request message, where the second request message is used torequest the information used for the PC5 interface-based communication;

sending, by the parameter configuration network element to the sessionmanagement function network element based on the second request message,the PCC rule used for the PC5 interface-based communication; and

receiving, by the session management function network element, the PCCrule from the parameter configuration network element, and obtaining theQoS rule according to the PCC rule.

The PCC rule used for the PC5 interface-based communication is obtainedbased on the second request message in the following implementations.

Manner 1: The parameter configuration network element obtains, based onthe second request message, the PCC rule from information stored in theparameter configuration network element.

Manner 2: The parameter configuration network element obtains the PCCrule from the UDR based on the second request message.

Manner 3: The parameter configuration network element obtains the PCCrule from a PCF based on the second request message.

For example, after identifying that the first request message is used torequest the information for the PC5 interface-based communication, forexample, when determining that the first request message is a specificmessage, such as the PDU session establishment request or the PDUsession modification request, or that the first request message carriesthe first indication information, the session management functionnetwork element may determine that the first request message is used torequest the information for the PC5 interface-based communication.Further, the session management function network element may send thesecond request message to the parameter configuration network element.After receiving the second request message, the parameter configurationnetwork element may obtain, from the information stored in the parameterconfiguration network element, the information used for the PC5interface-based communication, such as the PCC rule; or may obtain, fromthe subscription information of the terminal (where for example, theparameter configuration network element may obtain the subscriptioninformation of the terminal from the UDR), the PCC rule used for the PC5interface-based communication; or may obtain, from the PCF, the PCC ruleused for the PC5 interface-based communication.

Optionally, in the fourth implementation scenario of the foregoingembodiment, the core network element is the mobility management networkelement, and the method further includes:

sending, by the mobility management network element, a second requestmessage to the parameter configuration network element based on thefirst request message, where the second request message is used torequest the information used for the PC5 interface-based communication;

sending, by the parameter configuration network element to the mobilitymanagement network element based on the second request message, the QoSrule used for the PC5 interface-based communication; and receiving, bythe mobility management network element, the QoS rule from the parameterconfiguration network element.

The QoS rule used for the PC5 interface-based communication is obtainedbased on the second request message in the following implementations.

Manner 1: The parameter configuration network element obtains, based onthe second request message, the QoS rule from information stored in theparameter configuration network element.

Manner 2: The parameter configuration network element obtains the QoSrule from the UDR based on the second request message.

Manner 3: The parameter configuration network element obtains the QoSrule from a PCF based on the second request message.

For example, after receiving the first request message, the mobilitymanagement network element may send the second request message to theparameter configuration network element. After receiving the secondrequest message, the parameter configuration network element may obtain,from the information stored in the parameter configuration networkelement, the information used for the PC5 interface-based communication,such as the QoS rule; or may obtain, from the subscription informationof the terminal (where for example, the parameter configuration networkelement may obtain the subscription information of the terminal from theUDR), the QoS rule used for the PC5 interface-based communication; ormay obtain, from the PCF, the QoS rule used for the PC5 interface-basedcommunication.

Optionally, with reference to the third or the fourth implementationscenario, the second request message further includes second indicationinformation, where the second indication information is used to indicatethat the second request message is used to request the information usedfor the PC5 interface-based communication; or the second indicationinformation is used to indicate that the second request message is usedto request the information used for the V2X communication. Theinformation used for the V2X communication includes the information forthe PC5 interface-based communication. The second request message may bean Npcf_SMPolicyControl_Create message (for example, may include theSUPI, the PDU session ID, a PDU session type, the DNN, or an accesstype) sent by the SMF to a PCF, an Npcf_AMPolicyControl_Create message(for example, may include the SUPI) sent by the AMF to the PCF, a newmessage (for example, may include the SUPI) sent by the AMF to a V2Xcontrol function, or an Nsmf_PDUSession_CreateSMContext Request message(for example, may include the SUPI, the DNN, the S-NSSAI, the PDUsession ID, or an N1 SM container (the PDU session establishmentrequest)) sent by the AMF to the SMF.

Optionally, with reference to the first implementation scenario, thecore network element may further send third indication information tothe base station, and the base station may receive the third indicationinformation from the core network element. The third indicationinformation may be used to indicate that the QoS profile is used for thePC5 interface-based communication.

Further optionally, with reference to the third or the fourthimplementation scenario, the parameter configuration network element mayfurther indicate, to the core network element, that the information usedfor the PC5 interface-based communication is used for the PC5interface-based communication. For example, if the information that isused for the PC5 interface-based communication and that is sent by theparameter configuration network element to the core network element isthe PCC rule, the parameter configuration network element may furthersend fourth indication information to the core network element. The corenetwork element may further receive the fourth indication informationfrom the parameter configuration network element, where the fourthindication information may be used to indicate that the PCC rule is usedfor the PC5 interface-based communication. For another example, if theinformation that is used for the PC5 interface-based communication andthat is sent by the parameter configuration network element to the corenetwork element is the QoS rule and/or the QoS profile, the parameterconfiguration network element may further send fourth indicationinformation to the core network element. The core network elementreceives the fourth indication information from the parameterconfiguration network element, where the fourth indication informationmay be used to indicate that the QoS rule and/or the QoS profile are/isused for the PC5 interface-based communication.

Optionally, with reference to the third or the fourth implementationscenario, the parameter configuration network element may be a PCFnetwork element (PCF for short below), a V2X parameter configurationnetwork element such as the V2X control function, or a sessionmanagement function network element such as an SMF. When the parameterconfiguration network element is the V2X parameter configuration networkelement, the V2X parameter configuration network element may furthersend a third request message to the PCF network element, where the thirdrequest message is used to request, from the PCF, the information usedfor the PC5 interface-based communication. Further, the PCF may send, tothe V2X parameter configuration network element based on the thirdrequest message, the PCC rule for the PC5 interface-based communication,and the V2X parameter configuration network element may receive the PCCrule that is used for the PC5 interface-based communication and that issent by the PCF. Alternatively, the PCF may send, to the V2X parameterconfiguration network element based on the third request message, theQoS rule and/or the QoS profile that are/is used for the PC5interface-based communication, and the V2X parameter configurationnetwork element may receive the QoS rule and/or the QoS profile thatare/is used for the PC5 interface-based communication and that are/issent by the PCF. A manner in which the PCF sends, to the V2X parameterconfiguration network element based on the third request message, theinformation used for the PC5 interface-based communication is similar tothe foregoing manner in which the parameter configuration networkelement sends, based on the second request message, the information usedfor the PC5 interface-based communication. Details are not describedherein again. For example, the third request message may be a newmessage (for example, may include the SUPI). Further optionally, thethird request message may further include fifth indication information,where the fifth indication information may be used to indicate that thethird request message is used to request the information used for thePC5 interface-based communication; or the fifth indication informationmay be used to indicate that the third request message is used torequest the information used for the V2X communication, and theinformation used for the V2X communication includes the information forthe PC5 interface-based communication. Further optionally, the PCF mayfurther send sixth indication information to the V2X parameterconfiguration network element, where the sixth indication informationmay be used to indicate that the PCC rule is used for the PC5interface-based communication, or may be used to indicate that the QoSrule and/or the QoS profile are/is used for the PC5 interface-basedcommunication.

Further optionally, when the parameter configuration network element isthe SMF, the SMF may further send a third request message to the PCFnetwork element, where the third request message is used to request,from the PCF, the information used for the PC5 interface-basedcommunication. Further, the PCF may send, to the SMF based on the thirdrequest message, the PCC rule for the PC5 interface-based communication,and the SMF may receive the PCC rule that is used for the PC5interface-based communication and that is sent by the PCF.Alternatively, the PCF may send, to the SMF based on the third requestmessage, the QoS rule and/or the QoS profile that are/is used for thePC5 interface-based communication, and the SMF may receive the QoS ruleand/or the QoS profile that are/is used for the PC5 interface-basedcommunication and that are/is sent by the PCF. The third request messagemay be an Npcf_SMPolicyControl_Create message (the SUPI, the PDU sessionID, the PDU session type, the DNN, or the access type).

Further optionally, with reference to the first implementation scenario,the third indication information may further be used to indicate thatthe QoS rule is used for the PC5 interface-based communication, and thebase station may further forward the third indication information to theterminal. Alternatively, the core network element may further sendseventh indication information to the terminal, where the seventhindication information may be used to indicate that the QoS rule is usedfor the PC5 interface-based communication.

Further optionally, with reference to the first, the second, the third,or the fourth implementation scenario, the core network element may skiptriggering establishment of (does not establish) an N3 tunnel and an N4tunnel for the PDU session. For example, when the first request messageis the PDU session establishment request or the PDU session modificationrequest, the core network element may skip triggering, based on thefirst request message, the establishment of the N3 tunnel and the N4tunnel for the PDU session. For another example, when the first requestmessage (for example, the new message) carries the first indicationinformation, the core network element skips triggering the establishmentof the N3 tunnel and the N4 tunnel. For still another example, when thecore network element receives the fourth indication information, thecore network element skips triggering the establishment of the N3 tunneland the N4 tunnel. Further, the base station may further not establishan air-interface DRB and/or an N3 tunnel for the PDU session. Forexample, the base station may skip triggering, based on the firstrequest message, the establishment of the air-interface DRB and/or theN3 tunnel for the PDU session. For another example, when the firstrequest message carries the first indication information, the basestation skips triggering the establishment of the air-interface DRBand/or the N3 tunnel for the PDU session. For still another example,when the base station receives the third indication information, thebase station skips triggering the establishment of the air-interface DRBand/or the N3 tunnel for the PDU session. Alternatively, the basestation skips triggering establishment of an N3 tunnel for the PDUsession, but may establish an air-interface DRB, to reuse an existingscheduling mechanism such as a Uu interface scheduling mechanism. Whenidentifying that the PC5 interface-based communication is to beperformed, the base station schedules a resource used for the PC5interface-based communication, thereby reducing complexity ofair-interface resource scheduling. The N3 tunnel may be a tunnel betweenthe base station and a user plane function (UPF for short) networkelement, and the N4 tunnel may be a tunnel between the SMF and the UPF.That the core network element skips triggering the establishment of theN3 tunnel for the PDU session may mean that information sent by the SMFto the base station does not include core network tunnel information ofthe PDU session, and the core network tunnel information is used toestablish the N3 tunnel for the PDU session. That the base station skipstriggering the establishment of the N3 tunnel for the PDU session maymean that information returned by the base station to the SMF does notinclude base station tunnel information, and the base station tunnelinformation is used to establish the N3 tunnel for the PDU session. Thatthe core network element skips triggering the establishment of the N4tunnel for the PDU session may mean that the SMF does not send an N4interface session establishment request message N4 session establishmentrequest message to the UPF for the PDU session.

Optionally, with reference to the first, the second, the third, or thefourth implementation scenario, when it is determined (for example,based on the first request message, the first indication information,and/or the third indication information) that the PDU session is usedfor the PC5 interface-based communication, and there is no datatransmission on the PDU session, the base station skips initiating anetwork release (AN release) procedure. For example, even though a timeris set and expires, the AN release procedure is not initiated if thereis no data transmission on the PDU session.

Optionally, with reference to the first, the second, the third, or thefourth implementation scenario, when it is determined that the PDUsession is used for the PC5 interface-based communication and there isno data transmission on the PDU session, the core network element suchas the SMF, the base station, and/or the terminal skip/skips initiatinga PDU session deactivation (selective deactivation of UP connection ofan existing PDU session) procedure. For example, even though a timer isset and expires, the PDU session deactivation procedure is not initiatedif there is no data transmission on the PDU session.

Further optionally, with reference to the first, the second, the third,or the fourth implementation scenario, the core network element mayfurther store, for example, in context information of the terminal, theinformation (for example, the PCC rule, or the QoS rule and/or the QoSprofile) used for the PC5 interface-based communication. Optionally, thecore network element may further add an indication for the informationused for the PC5 interface-based communication, to indicate that theinformation is used for the PC5 interface-based communication. Forexample, the core network element may store the first indicationinformation, the fourth indication information or one piece of newlyadded indication information in the context information of the terminal.Alternatively, the core network element may indicate, in another manner,that the information is used for the PC5 interface-based communication.This is not limited in this application. Similarly, the base station mayfurther store the QoS profile in the context information of theterminal, and may add an indication to indicate that the QoS profile isused for the PC5 interface-based communication. Details are notdescribed herein again. In this way, the core network element and thebase station can quickly identify that the stored informationcorresponds to the PC5 interface-based communication, to prevent theinformation from being inadvertently deleted.

Further optionally, the foregoing indication information such as thefirst indication information, the second indication information, thethird indication information, the fourth indication information, thefifth indication information, the sixth indication information, and theseventh indication information may be the same (where some indicationinformation is the same or all the indication information is the same),or may be different (where some indication information is different orall the indication information is different). This is not limited inthis application. For example, the foregoing indication information maybe indicated by using same mark information such as a PC5 indication.

In another optional embodiment, the core network element mayalternatively obtain only the QoS profile, and send the QoS profile tothe base station; and does not need to obtain the QoS rule.Alternatively, the core network element obtains only the QoS rule, andsends the QoS rule to the terminal; and does not need to obtain the QoSprofile.

FIG. 2 b is a schematic interaction diagram of another communicationmethod according to an embodiment of the present invention. As shown inFIG. 2 b , the method may include the following steps.

2101. A base station receives a first request message from a terminal,where the first request message is used to request information used forPC5 interface-based communication of the terminal.

2102. The base station sends the first request message to a core networkelement.

2103. The base station receives, from the core network element, a QoSrule used for the PC5 interface-based communication, and sends the QoSrule to the terminal.

Specifically, the terminal may send the first request message to thebase station. The base station receives the first request message, andmay forward the first request message to the core network element.Further, the core network element may send, to the base station based onthe first request message, the information such as the QoS rule that isused for the PC5 interface-based communication. The base station mayreceive the QoS rule sent by the core network element, and may forwardthe QoS rule to the terminal. The terminal may receive the QoS rule sentby the base station. For descriptions of the first request message and aprocess of communication between the base station and another networkelement, refer to the related descriptions of the embodiment in FIG. 2 a. Details are not described herein again.

FIG. 3 is a schematic interaction diagram of a communication methodaccording to an embodiment of the present invention. As shown in FIG. 3, the method may include the following steps.

301. A terminal sends a first request message to a session managementfunction network element, where the first request message is used torequest information used for PC5 interface-based communication of theterminal.

Specifically, the terminal may send the first request message to a basestation, and then the base station may forward the first request messageto the session management function network element. In other words, theterminal may send the first request message to the session managementfunction network element through the base station. The first requestmessage may be used to request the information used for the PC5interface-based communication of the terminal, or the first requestmessage may be used to request information used for V2X communication orother information, where the information used for the V2X communicationor the other information includes the information for the PC5interface-based communication of the terminal.

Optionally, the first request message may be a message such as a PDUsession establishment request or a PDU session modification request, ormay be a newly added message or the like. This is not limited in thisapplication.

Further optionally, the first request message may further include firstindication information. The first indication information may be used toindicate that the first request message is used to request theinformation used for the PC5 interface-based communication.Alternatively, the first indication information may be used to indicatethat the first request message is used to request the information usedfor the V2X communication. The information used for the V2Xcommunication includes the information for the PC5 interface-basedcommunication.

302. The session management function network element sends a secondrequest message to a parameter configuration network element based onthe first request message, where the second request message is used torequest the information used for the PC5 interface-based communication.

Optionally, the second request message may include second indicationinformation, where the second indication information may be used toindicate that the second request message is used to request theinformation used for the PC5 interface-based communication.Alternatively, the second indication information may be used to indicatethat the first request message is used to request the information usedfor the V2X communication. The information used for the V2Xcommunication includes the information for the PC5 interface-basedcommunication.

303. The parameter configuration network element sends, to the sessionmanagement function network element based on the second request message,a PCC rule used for the PC5 interface-based communication.

Specifically, the parameter configuration network element may receivethe second request message sent by the session management functionnetwork element, then may obtain, based on the second request message,the PCC rule used for the PC5 interface-based communication, and maysend the PCC rule to the session management function network element.

304. The session management function network element obtains a QoS ruleand/or a QoS profile according to the PCC rule.

Specifically, the session management function network element mayreceive, from the parameter configuration network element, the PCC ruleused for the PC5 interface-based communication, and then may generatethe QoS rule and/or the QoS profile according to the PCC rule, to obtainthe QoS rule and/or the QoS profile that are/is used for the PC5interface-based communication.

Further optionally, the session management function network element maystore the QoS rule and/or the QoS profile in context information of theterminal, and may add an indication to indicate that the QoS rule and/orthe QoS profile are/is used for the PC5 interface-based communication,for example, may associate the first indication information with the QoSrule and/or the QoS profile, and store, in the context information, thefirst indication information and the QoS rule and/or the QoS profilethat are associated, to mark that the QoS rule and/or the QoS profileare/is used for the PC5 interface-based communication.

305. The session management function network element sends, to theterminal, the QoS rule used for the PC5 interface-based communication.

306. The session management function network element sends, to the basestation, the QoS profile used for the PC5 interface-based communication.

Further, if the session management function network element obtains,according to the PCC rule, the QoS rule used for the PC5 interface-basedcommunication, the session management function network element may send,to the terminal through the base station, the QoS rule used for the PC5interface-based communication. If the session management functionnetwork element obtains, according to the PCC rule, the QoS profile usedfor PC5 interface-based communication, the session management functionnetwork element may send, to the base station, the QoS profile used forthe PC5 interface-based communication. The terminal may receive the QoSrule. The base station may receive the QoS profile.

Further optionally, the session management function network element mayfurther send third indication information to the base station, and thebase station may receive the third indication information from thesession management function network element. The third indicationinformation may be used to indicate that the QoS profile is used for thePC5 interface-based communication.

Further optionally, the parameter configuration network element mayfurther send fourth indication information to the session managementfunction network element. The session management function networkelement may further receive the fourth indication information from theparameter configuration network element, where the fourth indicationinformation may be used to indicate that the PCC rule is used for thePC5 interface-based communication.

307. The terminal obtains scheduled-resource information according tothe QoS rule, and sends a V2X message on a resource corresponding to thescheduled-resource information.

Further optionally, the session management function network element mayfurther skip triggering establishment of an N3 tunnel and an N4 tunnelfor a PDU session, and the base station may further skip triggeringestablishment of an air-interface DRB and an N3 tunnel for the PDUsession. For details, refer to the related descriptions of theembodiment shown in FIG. 2 a , and the details are not described hereinagain.

Further optionally, the base station may store the QoS profile incontext information of the terminal, and may add an indication toindicate that the QoS profile is used for the PC5 interface-basedcommunication, for example, may associate the first indicationinformation with the QoS profile and store, in the context information,the first indication information and the QoS profile that areassociated; or may associate the third indication information with theQoS profile and store, in the context information, the third indicationinformation and the QoS profile that are associated, to mark that theQoS profile is used for the PC5 interface-based communication. In thisway, the base station can quickly identify that the stored QoS profilecorresponds to the PC5 interface-based communication, to prevent theinformation from being inadvertently deleted. A reason is as follows: Ifthe base station cannot identify the stored QoS profile and does notestablish the air-interface DRB or the N3 tunnel for the PDU session,the base station may delete the QoS profile.

Optionally, when it is determined that the PDU session is used for thePC5 interface-based communication and there is no data transmission onthe PDU session, the session management function network element, thebase station, and/or the terminal skip/skips initiating a PDU sessiondeactivation procedure, and the base station may further skip initiatingan release procedure. For details, refer to the related descriptions ofthe embodiment shown in FIG. 2 a , and the details are not describedherein again.

Optionally, the scheduled-resource information may be requested by theterminal from the base station, or may be determined by the terminalaccording to the QoS rule. For details, refer to the relateddescriptions of the embodiment shown in FIG. 2 a , and the details arenot described herein again. Further, the terminal may send the V2Xmessage on the resource corresponding to the scheduled-resourceinformation.

It should be understood that, in another optional embodiment, thesession management function network element may alternatively send, tothe terminal, a QoS rule that is stored in the session managementfunction network element and that is used for the PC5 interface-basedcommunication, and the terminal may receive the QoS rule; and/or thesession management function network element may alternatively send, tothe base station, a QoS profile that is stored in the session managementfunction network element and that is used for the PC5 interface-basedcommunication, and the base station may receive the QoS profile. Inanother optional embodiment, if the base station does not receive theQoS profile sent by the session management function network element, thebase station may alternatively determine the scheduled-resourceinformation for the terminal based on a QoS profile stored in the basestation. If the terminal does not receive the QoS rule from the sessionmanagement function network element, the terminal may alternativelydetermine the scheduled-resource information based on a QoS rule storedin the terminal.

In this embodiment of the present invention, the terminal may send, tothe session management function network element, the first requestmessage used to request the information used for the PC5 interface-basedcommunication of the terminal, so that the session management functionnetwork element can send, to the parameter configuration network elementbased on the first request message, the second request message used torequest the information used for the PC5 interface-based communicationof the terminal, and the parameter configuration network element cansend, to the session management function network element based on thesecond request message, the PCC rule used for the PC5 interface-basedcommunication. Further, after obtaining the QoS rule and the QoS profileaccording to the PCC rule, the session management function networkelement can send, to the terminal, the QoS rule used for the PC5interface-based communication, and send the QoS profile to the basestation. In this way, QoS information used for the PC5 interface-basedcommunication can be obtained from a network side, so that the terminaland the base station determine, based on the QoS rule and/or the QoSprofile, the scheduled-resource information for the terminal to performa V2X service, and there is no need to separately reconfigure a PPPPmapping mechanism for the terminal side and the base station side when anew type of V2X message needs to be deployed. This helps improvereliability and flexibility of the obtained QoS information, andprevents the QoS information from being modified without authorization,thereby reducing improper resource allocation.

FIG. 4 is a schematic interaction diagram of still another communicationmethod according to an embodiment of the present invention. As shown inFIG. 4 , the method may include the following steps.

401. A parameter configuration network element obtains a PCC rule usedfor PC5 interface-based communication of a terminal.

Optionally, the PCC rule may be obtained by the parameter configurationnetwork element in a preset time interval, or may be obtained by theparameter configuration network element by receiving an indication froman application server, or may be obtained when it is detected that thePCC rule is updated, or may be obtained in another manner. This is notlimited in this application. For example, the terminal triggers a V2Xapplication, for example, may request a V2X service from the applicationserver. After receiving the request, the application server may indicatethe parameter configuration network element to trigger establishment ofa corresponding QoS flow for the V2X service. In this way, informationsuch as the PCC rule that is used for the PC5 interface-basedcommunication and that corresponds to the QoS flow is configured on theterminal. For another example, a network side such as the applicationserver triggers, to the terminal, a V2X service corresponding to a V2Xapplication, and indicates the parameter configuration network elementto trigger establishment of a PDU session for the V2X service, toconfigure information such as the PCC rule that is used for the PC5interface-based communication and that corresponds to the PDU session onthe terminal.

402. The parameter configuration network element sends the PCC rule to asession management function network element.

Optionally, the parameter configuration network element sends firstindication information to the session management function networkelement, where the first indication information is used to indicate thatthe PCC rule is used for the PC5 interface-based communication.

Specifically, after obtaining the PCC rule, the parameter configurationnetwork element may send the PCC rule to the session management functionnetwork element, and may send indication information, namely, the firstindication information, to the session management function networkelement, to indicate that the PCC rule is used for the PC5interface-based communication. For example, one message may carry boththe PCC rule and the first indication information.

403. The session management function network element obtains a QoS ruleand/or a QoS profile according to the PCC rule.

404. The session management function network element sends the QoS ruleto the terminal.

Optionally, the session management function network element sends secondindication information to the terminal, where the second indicationinformation is used to indicate that the QoS rule is used for the PC5interface-based communication.

405. The session management function network element sends the QoSprofile to a base station.

Specifically, for steps 403, 404, and 405, refer to the relateddescriptions of steps 304, 305, and 306 in the embodiment shown in FIG.3 . Details are not described herein again.

Optionally, the session management function network element sends thirdindication information to the base station, where the third indicationinformation is used to indicate that the QoS profile is used for the PC5interface-based communication.

Further, if the session management function network element obtains,according to the PCC rule, the QoS rule used for the PC5 interface-basedcommunication, when sending the QoS rule to the terminal through thebase station, the session management function network element mayfurther send one piece of indication information, namely, the secondindication information, to the terminal through the base station, toindicate that the QoS rule is used for the PC5 interface-basedcommunication. If the session management function network elementobtains, according to the PCC rule, the QoS profile used for the PC5interface-based communication, when sending the QoS profile to the basestation, the session management function network element may furthersend one piece of indication information, namely, the third indicationinformation, to the base station, to indicate that the QoS profile isused for the PC5 interface-based communication. The terminal may receivethe QoS rule and the second indication information. The base station mayreceive the QoS profile and the third indication information. Furtheroptionally, the second indication information and the third indicationinformation may be independent indication information, to be specific,separately indicate that corresponding information is used for the PC5interface-based communication. Alternatively, the second indicationinformation and the third indication information may be a same piece ofindication information, to be specific, one piece of indicationinformation may be used to indicate that the QoS rule and the QoSprofile are used for the PC5 interface-based communication. For example,the session management function network element may send one piece ofindication information to the base station to indicate that the QoS ruleand the QoS profile are used for the PC5 interface-based communication.After receiving the piece of indication information, the base stationmay send, to the terminal, the QoS rule that carries the piece ofindication information. This is not limited in this application.

Further, the terminal may obtain scheduled-resource informationaccording to the QoS rule, and send a V2X message on a resourcecorresponding to the scheduled-resource information. Details are notdescribed herein.

It should be understood that this embodiment may be independentlyimplemented, or may be jointly implemented with one or more of theforegoing embodiments in FIG. 2 a to FIG. 3 . For example, thisembodiment may be applied to update of the QoS rule and/or the QoSprofile that are/is used for the PC5 interface-based communication. Thisis not limited in this application.

In this embodiment of the present invention, the parameter configurationnetwork element can obtain the PCC rule used for the PC5 interface-basedcommunication, and send, to the session management function networkelement, the PCC rule that carries the indication information used forthe PC5 interface-based communication. Further, after obtaining the QoSrule and the QoS profile according to the PCC rule, the sessionmanagement function network element can send, to the terminal, the QoSrule that carries the indication information used for the PC5interface-based communication; and send, to the base station, the QoSprofile that carries the indication information used for the PC5interface-based communication. In this way, QoS information used for thePC5 interface-based communication can be obtained from a network side,so that the terminal and the base station determine, based on the QoSrule and the QoS profile, the scheduled-resource information for theterminal to perform a V2X service. This helps improve reliability andflexibility of the obtained QoS information, and prevents the QoSinformation from being modified without authorization, thereby reducingimproper resource allocation.

FIG. 5 is a schematic interaction diagram of a communication methodaccording to an embodiment of the present invention. As shown in FIG. 5, the method may include the following steps.

501. A terminal sends a first request message to a mobility managementnetwork element, where the first request message is used to requestinformation used for PC5 interface-based communication of the terminal.

Specifically, the terminal may send the first request message to a basestation, and then the base station may forward the first request messageto the mobility management network element. In other words, the terminalmay send the first request message to the mobility management networkelement through the base station. The first request message may be usedto request the information used for the PC5 interface-basedcommunication of the terminal, or the first request message may be usedto request information used for V2X communication or other information,where the information used for the V2X communication or the otherinformation includes the information for the PC5 interface-basedcommunication of the terminal.

Optionally, the first request message may be a message such as aregistration request or a service request, or may be a newly addedmessage or the like. This is not limited in this application. The firstrequest message may be used to request a V2X parameter, and the V2Xparameter needs to include the information used for the PC5interface-based communication of the terminal.

Further optionally, the first request message may further include firstindication information. The first indication information may be used toindicate that the first request message is used to request theinformation used for the PC5 interface-based communication.Alternatively, the first indication information may be used to indicatethat the first request message is used to request the information usedfor the V2X communication. The information used for the V2Xcommunication includes the information for the PC5 interface-basedcommunication.

502. The mobility management network element sends a second requestmessage to a parameter configuration network element based on the firstrequest message, where the second request message is used to request theinformation used for the PC5 interface-based communication.

Optionally, the second request message may be an existing message, ormay be a newly added message. For example, the parameter configurationnetwork element may be a PCF, and the second request message may be anaccess and mobility policy control create Npcf_AMPolicyControl_Createmessage. Alternatively, the parameter configuration network element is aV2X parameter configuration network element such as a V2X controlfunction, and the second request message may be a V2X parameter requestmessage. Examples are not listed one by one herein.

Optionally, the second request message may include second indicationinformation, where the second indication information may be used toindicate that the second request message is used to request theinformation used for the PC5 interface-based communication.Alternatively, the second indication information may be used to indicatethat the second request message is used to request the information usedfor the V2X communication. The information used for the V2Xcommunication includes the information for the PC5 interface-basedcommunication.

503. The parameter configuration network element sends, to the mobilitymanagement network element based on the second request message, a QoSrule and/or a QoS profile that are/is used for the PC5 interface-basedcommunication.

Specifically, the parameter configuration network element may receivethe second request message sent by the mobility management networkelement, then may obtain, based on the second request message, the QoSrule and/or the QoS profile that are/is used for the PC5 interface-basedcommunication, and sends the QoS rule and/or the QoS profile to themobility management network element. The parameter configuration networkelement may obtain a PCC rule used for the PC5 interface-basedcommunication, and then obtain the QoS rule and/or the QoS profileaccording to the PCC rule. Alternatively, the QoS rule and/or the QoSprofile may be received by the parameter configuration network elementfrom another network element such as a PCF.

504. The mobility management network element sends, to the terminal, theQoS rule used for the PC5 interface-based communication.

505. The mobility management network element sends, to the base station,the QoS profile used for the PC5 interface-based communication.

Specifically, the mobility management network element may receive, fromthe parameter configuration network element, the QoS rule and/or the QoSprofile that are/is used for the PC5 interface-based communication. Ifthe mobility management network element receives the QoS rule, themobility management network element may send, to the terminal throughthe base station, the QoS rule used for the PC5 interface-basedcommunication, in other words, the mobility management network elementmay perform step 504. If the mobility management network elementreceives the QoS profile, the mobility management network element maysend, to the base station, the QoS profile used for the PC5interface-based communication, in other words, the mobility managementnetwork element may perform step 505. Further optionally, the mobilitymanagement network element may further send third indication informationto the base station, and the base station may receive the thirdindication information from the mobility management network element. Thethird indication information may be used to indicate that the QoSprofile is used for the PC5 interface-based communication.

In another optional embodiment, alternatively, the mobility managementnetwork element may only send, to the terminal, the QoS rule used forthe PC5 interface-based communication. For example, in a non-coveragescenario, the mobility management network element may only send, to theterminal, the QoS rule used for the PC5 interface-based communication,and does not send, to the base station, the QoS profile used for the PC5interface-based communication. In another optional embodiment,alternatively, the mobility management network element may only send, tothe base station, the QoS profile used for the PC5 interface-basedcommunication. For example, when the terminal changes from an idle stateto a connected state, the mobility management network element may onlysend, to the base station, the QoS profile used for the PC5interface-based communication, and does not send, to the terminal, theQoS rule used for the PC5 interface-based communication.

Further optionally, the parameter configuration network element mayfurther send fourth indication information to the mobility managementnetwork element. The mobility management network element may furtherreceive the fourth indication information from the parameterconfiguration network element, where the fourth indication informationmay be used to indicate that the QoS rule and/or the QoS profile are/isused for the PC5 interface-based communication.

Optionally, when it is determined that a PDU session is used for the PC5interface-based communication and there is no data transmission on thePDU session, the base station may skip initiating an AN releaseprocedure. For details, refer to the related descriptions of theembodiment shown in FIG. 2 a , and the details are not described hereinagain.

506. The terminal obtains scheduled-resource information according tothe QoS rule, and sends a V2X message on a resource corresponding to thescheduled-resource information.

Optionally, when the parameter configuration network element is not aPCF but is, for example, a V2X control function, the V2X controlfunction may further send a third request message to the PCF, where thethird request message is used to request, from the PCF, the informationused for the PC5 interface-based communication. Further, the PCF maysend, to the V2X control function based on the third request message,the PCC rule for the PC5 interface-based communication, and the V2Xcontrol function may receive the PCC rule. Alternatively, the PCF maysend, to the V2X control function based on the third request message,the QoS rule and/or the QoS profile that are/is used for the PC5interface-based communication, and the V2X control function may receivethe QoS rule and/or the QoS profile that are/is used for the PC5interface-based communication and that are/is sent by the PCF. Furtheroptionally, the third request message may further include fifthindication information, where the fifth indication information may beused to indicate that the third request message is used to request theinformation used for the PC5 interface-based communication; or the fifthindication information may be used to indicate that the third requestmessage is used to request the information used for the V2Xcommunication, and the information used for the V2X communicationincludes the information for the PC5 interface-based communication.Further optionally, the PCF may further send sixth indicationinformation to the V2X control function, where the sixth indicationinformation may be used to indicate that the PCC rule is used for thePC5 interface-based communication, or may be used to indicate that theQoS rule and/or the QoS profile are/is used for the PC5 interface-basedcommunication.

Optionally, the scheduled-resource information may be requested by theterminal from the base station, or may be determined by the terminalaccording to the QoS rule. For details, refer to the relateddescriptions of the embodiment shown in FIG. 2 a , and the details arenot described herein again. Further, the terminal may send the V2Xmessage on the resource corresponding to the scheduled-resourceinformation.

It should be understood that, in another optional embodiment, themobility management network element may alternatively send, to theterminal, a stored QoS rule (stored in the mobility management networkelement or a UDM) used for the PC5 interface-based communication, andthe terminal may receive the QoS rule; and/or the mobility managementnetwork element may alternatively send, to the base station, a storedQoS profile used for the PC5 interface-based communication, and the basestation may receive the QoS profile. In another optional embodiment, ifthe base station does not receive the QoS profile sent by the mobilitymanagement network element, the base station may alternatively determinethe scheduled-resource information for the terminal based on a QoSprofile stored in the base station. If the terminal does not receive theQoS rule from the mobility management network element, the terminal mayalternatively determine the scheduled-resource information based on aQoS rule stored in the terminal.

In this embodiment of the present invention, the terminal may send, tothe mobility management network element, the first request message usedto request the information used for the PC5 interface-basedcommunication of the terminal, so that the mobility management networkelement can send, to the parameter configuration network element basedon the first request message, the second request message used to requestthe information used for the PC5 interface-based communication of theterminal, and the parameter configuration network element can send, tothe mobility management network element based on the second requestmessage, the QoS rule and the QoS profile that are used for the PC5interface-based communication. Further, the mobility management networkelement can send, to the terminal, the QoS rule used for the PC5interface-based communication, and send the QoS profile to the basestation. In this way, QoS information used for the PC5 interface-basedcommunication can be obtained from a network side, so that the terminaland the base station determine, based on the QoS rule and/or the QoSprofile, the scheduled-resource information for the terminal to performa V2X service. This helps improve reliability and flexibility of theobtained QoS information, and prevents the QoS information from beingmodified without authorization, thereby reducing improper resourceallocation.

FIG. 6 is a schematic interaction diagram of a communication methodaccording to an embodiment of the present invention. As shown in FIG. 6, the method may include the following steps.

601. A parameter configuration network element obtains a QoS rule and/ora QoS profile that are/is used for PC5 interface-based communication ofa terminal.

Optionally, the QoS rule and/or the QoS profile may be obtained by theparameter configuration network element in a preset time interval, ormay be obtained by the parameter configuration network element byreceiving an indication from an application server, or may be obtainedwhen it is detected that a PCC rule is updated, or may be obtained inanother manner. This is not limited in this application. The QoS ruleand/or the QoS profile may be determined by the parameter configurationnetwork element according to an obtained PCC rule (where the PCC rule isobtained from stored information, is received from another networkelement such as a PCF, or is obtained in another manner); or may bereceived by the parameter configuration network element from the anothernetwork element such as the PCF. Details are not described herein.

602. The parameter configuration network element sends the QoS ruleand/or the QoS profile to a mobility management network element.

Optionally, the parameter configuration network element sends firstindication information to the mobility management network element, wherethe first indication information is used to indicate that the QoS ruleand/or the QoS profile are/is used for the PC5 interface-basedcommunication.

Specifically, after obtaining the QoS rule and/or the QoS profile, theparameter configuration network element may send the QoS rule and/or theQoS profile to the mobility management network element, and may sendindication information, namely, the first indication information, to themobility management network element, to indicate that the QoS ruleand/or the QoS profile are/is used for the PC5 interface-basedcommunication. For example, one message may carry both the firstindication information and the QoS rule and/or the QoS profile.

603. The mobility management network element sends the QoS rule to theterminal.

Optionally, the mobility management network element sends secondindication information to the terminal, where the second indicationinformation is used to indicate that the QoS rule is used for the PC5interface-based communication.

604. The mobility management network element sends the QoS profile to abase station.

Optionally, the mobility management network element sends thirdindication information to the base station, where the third indicationinformation is used to indicate that the QoS profile is used for the PC5interface-based communication.

Specifically, for steps 603 and 604, refer to the related descriptionsof steps 504 and 505 in the embodiment shown in FIG. 5 . Details are notdescribed herein again.

Further optionally, if the mobility management network element obtainsthe QoS rule used for the PC5 interface-based communication (where themobility management network element receives the QoS rule that is usedfor the PC5 interface-based communication and that is sent by theparameter configuration network element, or obtains a stored QoS ruleused for the PC5 interface-based communication), when sending the QoSrule to the terminal through the base station, the mobility managementnetwork element may further send one piece of indication information,namely, the second indication information, to the terminal through thebase station, to indicate that the QoS rule is used for the PC5interface-based communication. If the mobility management networkelement obtains the QoS profile used for the PC5 interface-basedcommunication (where the mobility management network element receivesthe QoS profile that is used for the PC5 interface-based communicationand that is sent by the parameter configuration network element, orobtains a stored QoS profile used for the PC5 interface-basedcommunication), when sending the QoS profile to the base station, themobility management network element may further send one piece ofindication information, namely, the third indication information, to thebase station, to indicate that the QoS profile is used for the PC5interface-based communication. The terminal may receive the QoS rule andthe second indication information. The base station may receive the QoSprofile and the third indication information. Further optionally, thesecond indication information and the third indication information maybe independent indication information, to be specific, separatelyindicate that corresponding information is used for the PC5interface-based communication. Alternatively, the second indicationinformation and the third indication information may be a same piece ofindication information, to be specific, one piece of indicationinformation may be used to indicate that the QoS rule and the QoSprofile are used for the PC5 interface-based communication. This is notlimited in this application.

Further, the terminal may obtain scheduled-resource informationaccording to the QoS rule, and send a V2X message on a resourcecorresponding to the scheduled-resource information. Details are notdescribed herein.

It should be understood that this embodiment may be independentlyimplemented, or may be jointly implemented with the embodiment in FIG. 2a or FIG. 5 . For example, this embodiment may be applied to update ofthe QoS rule and/or the QoS profile that are/is used for the PC5interface-based communication. This is not limited in this application.

In this embodiment of the present invention, the parameter configurationnetwork element can obtain the QoS rule and/or the QoS profile thatare/is used for the PC5 interface-based communication, and send, to themobility management network element, the QoS rule and/or the QoS profilethat carry/carries the indication information used for the PC5interface-based communication. Further, the mobility management networkelement can send, to the terminal, the QoS rule that carries theindication information used for the PC5 interface-based communication;and send, to the base station, the QoS profile that carries theindication information used for the PC5 interface-based communication.In this way, QoS information used for the PC5 interface-basedcommunication can be obtained from a network side, so that the terminaland the base station determine, based on the QoS rule and/or the QoSprofile, the scheduled-resource information for the terminal to performa V2X service. This helps improve reliability and flexibility of theobtained QoS information, and prevents the QoS information from beingmodified without authorization, thereby reducing improper resourceallocation.

An example in which the terminal is UE and the parameter configurationnetwork element is a PCF is used. FIG. 7 is a schematic diagram ofanother communications system.

As shown in FIG. 7 , the UE may communicate with an AMF and an SMFthrough an access network such as a radio access network (RAN for short)(which may be referred to as a (R)AN below), namely, a network in whicha base station connected to the UE is located. The AMF and the SMF maycommunicate with the PCF. Further, the communications system may furtherinclude network elements such as a UPF, a UDM, and a UDR. The accessnetwork such as the RAN may be a network including a plurality of 5G-RANnodes such as base stations, and is configured to implement a radiophysical layer function, resource scheduling and radio resourcemanagement, radio access control, and a mobility management function.Further, the RAN may be connected to the UPF, for example, connected tothe UPF via a user plane interface N3, to deliver data of the UE. TheRAN may further be connected to the AMF. For example, the RANestablishes a control plane signaling connection to the AMF via acontrol plane interface N2, to implement a function such as radio accessbearer control. For example, the AMF may be responsible for functionssuch as UE authentication, UE mobility management, network sliceselection, and SMF selection. The SMF is mainly responsible for allcontrol plane functions of UE session management, including UPFselection, IP address allocation, QoS management of a session, obtainingof a PCC rule (from the PCF), and the like. The PCF may configure, forthe UE, information including a PCC rule, a QoS rule, a QoS profile, andthe like that is used for PC5 interface-based communication. The UDR maystore subscription information of the UE, and the UDM may obtain thesubscription information of the UE from the UDR.

FIG. 8 a -1 and FIG. 8 a -2 are a schematic interaction diagram of stillanother communication method according to an embodiment of the presentinvention. As shown in FIG. 8 a -1 and FIG. 8 a -2, the communicationmethod provided in this embodiment of the present invention may be basedon the system architecture shown in FIG. 7 . For example, a firstrequest message is a PDU session establishment request, and a corenetwork element is the SMF. As shown in FIG. 8 a -1 and FIG. 8 a -2, themethod may include the following steps.

801. The UE sends, to the SMF, the PDU session establishment requestcarrying a PC5 indication.

When the UE needs to initiate a V2X service, and needs to obtain acorresponding QoS rule from the network, the UE may send the PDU sessionestablishment request to the SMF, in other words, initiate a PDU sessionestablishment procedure. The PDU session establishment request carriesthe PC5 indication, and the PC5 indication may be used to indicate thatthe PDU session establishment request is used to request informationused for PC5 interface-based communication, in other words, indicatethat information obtained through establishment of a PDU session is usedfor the PC5 interface-based communication.

Specifically, the UE initiates the establishment of the PDU session, andsends mobility management (MM for short) NAS signaling to the AMF, wherethe mobility management NAS signaling may include single network sliceselection assistance information (S-NSSAI for short), a data networkname (DNN for short), a PDU session identifier (PDU Session ID), or SMsignaling, for example, the PDU session establishment request. The PDUsession establishment request may carry a PDU type (PDU Type, indicatingwhether a type of the PDU session is IPv4 or IPv6) or a service andsession continuity mode (SSC mode, indicating the service and sessioncontinuity mode of the PDU session: in mode 1, an anchor (the UPF) of anIP address remains unchanged, and service continuity is supported; inmode 2, an anchor (the UPF) of an IP address is changeable, and thenetwork may first release a PDU session, and then indicate the UE toestablish a new PDU session; in mode 3, a new network connection isestablished for the UE, and then an old network connection is released).Optionally, the AMF may select an appropriate SMF. For example, the AMFmay select the SMF based on the S-NSSAI and the DNN. Further, the AMFmay send, to the SMF, a PDU session create session management contextrequest (Nsmf_PDUSession_CreateSMContext Request) message, where themessage includes the PDU session establishment request.

802. The SMF determines that the PDU session is used for the PC5interface-based communication.

803. The SMF sends, to the PCF, a request message used to request theinformation used for the PC5 interface-based communication of the UE.

The SMF may determine, based on the PC5 indication, that the informationused for the PC5 interface-based communication needs to be obtained, andthen may send the request message to the PCF, to request the informationused for the PC5 interface-based communication of the UE or informationfor V2X communication. Optionally, the SMF may further send, to the PCF,the request message including indication information, such as the PC5indication, used to indicate that the request message is used to requestthe information used for the PC5 interface-based communication of the UEor the information for the V2X communication. Optionally, the requestmessage may be a session management policy establishment or modificationrequest (session management policy establishment or modificationrequest) message. The PC5 indication may be used to indicate that thesession management policy establishment or modification request is usedto request the information used for the PC5 interface-basedcommunication. In another optional embodiment, the request message maynot need to carry the indication information such as the PC5 indication,because the PCF may not need to identify that the request message isused to request the information used for the PC5 interface-basedcommunication. For example, when there is no difference between QoSinformation (such as a PCC rule, a QoS rule, or a QoS profile) of a PC5interface and QoS information of a Uu interface, there is no need toidentify that the request message is used to request the informationused for the PC5 interface-based communication or Uu interface-basedcommunication. In this case, the indication information may not need tobe carried. It should be understood that if there is a differencebetween the QoS information of the PC5 interface and the QoS informationof the Uu interface, the request message needs to carry the indicationinformation such as the PC5 indication.

804. The PCF generates a PCC rule used for the PC5 interface-basedcommunication.

805. The PCF sends, to the SMF, the PCC rule used for the PC5interface-based communication.

When receiving the session management policy establishment ormodification request, the PCF may obtain the PCC rule used for the PC5interface-based communication, and may return the PCC rule to the SMF.For example, a session management policy establishment or modificationresponse (session management policy establishment or modificationresponse) message including the PCC rule may be sent to the SMF.

Specifically, if the SMF does not have SM-related subscriptioninformation of the UE, the SMF may obtain the subscription informationfrom the UDM. Optionally, the SM-related subscription information mayinclude an authorized PDU type(s), an authorized SSC mode(s), a defaultQoS attribute (Default QoS profile), or the like. Optionally, the SMFmay return a PDU session create session management context response(Nsmf_PDUSession_CreateSMContext Response) message to the AMF. Furtheroptionally, the SMF may further initiate a third-party authenticationand authorization procedure for the PDU session, so that the SMFdetermines, based on an authentication and authorization result, whetherto continue to perform the PDU session establishment procedure for thePDU session of the UE. Further optionally, the SMF may further selectthe PCF, and initiate PDU-CAN session establishment to the PCF, toobtain PCC rules of the PDU session. For example, the SMF may select anapproximate UPF for the PDU session based on a UE location, UPF load, aUPF capacity, the DNN, the PDU type, the SSC mode of the PDU session, orUE subscription, and allocate an IP address to the PDU session. Further,if an event subscribed by the PCF occurs, the SMF notifies the PCF ofthe event. If the PCC rule of the UE is updated, the PCF sends anupdated PCC rule to the SMF.

Optionally, the SMF may initiate an N4 session establishment procedureto the UPF for the PDU session, in other words, establish an N4 tunnel.An N4 session establishment/modification procedure (N4 SessionEstablishment/modification procedure) is performed between the SMF andthe UPF, to configure a packet detection rule (packet detection), areporting rule, core network tunnel information (CN tunnel info) on theUPF. Alternatively, because the information used for the PC5interface-based communication is obtained, the SMF may not establish theN4 tunnel for the PDU session, to reduce system signaling overheads.Further optionally, the SMF may further skip triggering establishment ofan N3 tunnel for the PDU session. In other words, the SMF may notestablish a backhaul tunnel for the PDU session.

806. The SMF sends, to the UE according to the PCC rule, a QoS rule usedfor the PC5 interface-based communication.

807. The SMF sends, to the base station according to the PCC rule, a QoSprofile used for the PC5 interface-based communication.

Specifically, after receiving the PCC rule, the SMF may obtain,according to the PCC rule, the QoS rule and the QoS profile that areused for the PC5 interface-based communication. Further, the SMF maysend, to the base station ((R)AN), an N2 interface session managementinformation (N2 SM info) message including the QoS profile used for thePC5 interface-based communication, and send, to the UE, a PDU sessionestablishment accept message including the QoS rule used for the PC5interface-based communication.

808. The base station determines that the QoS profile is used for thePC5 interface-based communication, and marks the QoS profile as beingused for the PC5 interface-based communication.

Specifically, the SMF sends parameter information of the PDU session tothe AMF. The parameter information includes N1 SM information (the PDUsession establishment accept message) sent to the UE, where the PDUsession establishment accept message may include one or more of (anauthorized QoS rule, the SSC mode, the S-NSSAI, an allocated IPv4address, and a session-AMBR); and the N2 SM information sent to the RAN,where the N2 SM information may include one or more of (the PDU sessionID, the QoS profile, the CN tunnel Info, the S-NSSAI, and thesession-AMBR). Further, the AMF may send, to the RAN, the N1 SMinformation and the N2 SM information that are received from the SMF.Optionally, the RAN exchanges RRC signaling with the UE, to establish anecessary air-interface resource for the PDU session. In addition, theRAN may send the N1 SM information to the UE. Optionally, the RAN mayfurther reply an N2 PDU Session Response message to the AMF, where theN2 PDU Session Response message may include the PDU session ID and N2 SMinformation (one or more of the PDU session ID, (R)AN tunnel info, or alist of accepted/rejected QoS profile(s)). Further optionally, the AMFmay send, to the SMF, the N2 SM information received from the RAN, theSMF may send the (R)AN tunnel info in the N2 SM information to the UPF,and the UPF may return a response message to the SMF. Optionally, if theN3 tunnel is not established for the PDU session, the N2 SM informationsent by the SMF to the RAN does not include the CN tunnel info, and theN2 SM information sent by the RAN to the SMF does not include the (R)ANtunnel info. Further, the SMF may return a response message to the AMF.If the PDU session fails to be established, the SMF notifies the AMFthat the establishment of the PDU session fails.

Optionally, if the RAN identifies that the received QoS profile is usedfor the PC5 interface-based communication, the RAN may mark the QoSprofile as being used for the PC5 interface-based communication. Forexample, the RAN stores the QoS profile in context information of theUE, and indicates that the QoS profile is used for the PC5interface-based communication. Optionally, the RAN skips establishmentof an air-interface DRB and/or a backhaul tunnel (for example, an N3tunnel) for the PDU session, to reduce the system signaling overheads.Alternatively, the RAN may still establish a DRB, to reuse a Uuinterface scheduling mechanism. Details are not described herein.

Optionally, even though there is no data transmission on all PDUsessions of the UE, the UE, the base station, and the SMF skipinitiating AN release. Further optionally, if a timer such as aninactivity timer is set, and there is no data transmission on all thePDU sessions, the AN release is not initiated even though the inactivitytimer expires.

Optionally, when it is determined that the PDU session is used for thePC5 interface-based communication and there is no data transmission onthe PDU session, the SMF, the base station, and/or the UE may skipinitiating a PDU session deactivation procedure. Details are notdescribed herein.

Further, the RAN may further reply the N2 PDU Session Response messagesuch as N2 PDU Session Request Ack to the AMF, where the N2 PDU SessionResponse message may include the PDU session ID, the N2 interfacesession management information N2 SM information, or the like. The N2 SMinformation may include the one or more of the PDU session identifier(PDU Session ID), base station tunnel information (the (R)AN tunnelinfo), or the list of accepted/rejected QoS profile(s) (List ofaccepted/rejected QoS profile) Further, the AMF may send, to the SMF,the N2 SM information received from the RAN, for example, may send, tothe SMF, an PDU session update session management context request(Nsmf_PDUSession_UpdateSMContext Request) message that includes the N2SM information. The SMF may send the (R)AN tunnel info in the N2 SMinformation to the UPF, and the UPF may return the response message tothe SMF. For example, the SMF may send the (R)AN tunnel info to the UPFthrough a PDU session modification procedure. Further, the SMF mayreturn the response message to the AMF. For example, the responsemessage may be an Nsmf_PDUSession_UpdateSMContext Response message. Itshould be understood that if the N3 tunnel is not established, the N2 SMinformation at least does not need to include the base station tunnelinformation ((R)AN tunnel info). Optionally, the PDU session identifiermay not need to be included.

It should be understood that, when the first request message is a PDUsession modification request message, the procedure of obtaining,through the PDU session modification procedure, the information used forthe PC5 interface-based communication is similar to the PDU sessionestablishment procedure, and details are not described herein again.

In this embodiment of the present invention, the UE may send, to theSMF, the PDU session establishment request used to request theinformation used for the PC5 interface-based communication of the UE, sothat the SMF can send, to the PCF based on the PDU session establishmentrequest, the request message used to request the information used forthe PC5 interface-based communication of the UE, and the PCF can send,to the SMF based on the request message, the PCC rule used for the PC5interface-based communication. Further, after obtaining the QoS rule andthe QoS profile according to the PCC rule, the SMF can send, to the UE,the QoS rule used for the PC5 interface-based communication, and sendthe QoS profile to the base station. In this way, QoS information usedfor the PC5 interface-based communication can be obtained from a networkside, so that the UE and the base station determine, based on the QoSrule and/or the QoS profile, scheduled-resource information for the UEto perform a V2X service. This helps improve reliability and flexibilityof the obtained QoS information, and prevents the QoS information frombeing modified without authorization.

FIG. 8 b -1 and FIG. 8 b -2 are a schematic interaction diagram of stillanother communication method according to an embodiment of the presentinvention. As shown in FIG. 8 b -1 and FIG. 8 b -2, the communicationmethod provided in this embodiment of the present invention may be basedon the system architecture shown in FIG. 7 . For example, a firstrequest message is a PDU session establishment request, and a corenetwork element is the SMF. As shown in FIG. 8 b -1 and FIG. 8 b -2, themethod may include the following steps.

8101. The UE sends a NAS message to the AMF, where the NAS messagecarries a PC5 indication and the PDU session establishment request.

When the UE needs to initiate a V2X service, and needs to obtain acorresponding QoS rule from the network, the UE may send, to the AMF,the NAS message carrying the PDU session establishment request andindication information such as the PC5 indication. The PC5 indicationmay be used to indicate that the PDU session establishment request isused to request information used for PC5 interface-based communication,in other words, indicate that information obtained through establishmentof a PDU session is used for the PC5 interface-based communication.

Specifically, the UE initiates the establishment of the PDU session, andsends MM NAS signaling to the AMF. The MM NAS signaling may includeS-NSSAI, a DNN, a PDU session ID, and SM signaling, for example, the PDUsession establishment request. The PDU session establishment request maycarry a PDU type (PDU Type, indicating whether a type of the PDU sessionis IPv4 or IPv6), or a service and session continuity mode. Optionally,the AMF may select an appropriate SMF. Details are not described herein.

8102. The AMF sends, to the SMF, the PC5 indication and the PDU sessionestablishment request.

8103. The SMF determines that the PDU session is used for the PC5interface-based communication.

8104. The SMF sends, to the PCF, a request message carrying the PC5indication.

8105. The PCF generates a PCC rule used for the PC5 interface-basedcommunication.

8106. The PCF sends, to the SMF, the PCC rule used for the PC5interface-based communication.

8107. The SMF obtains, according to the PCC rule, a QoS rule used forthe PC5 interface-based communication of the UE, and sends the QoS ruleto the AMF.

8108. The AMF sends, to the UE through the base station, the QoS ruleused for the PC5 interface-based communication.

8109. The SMF obtains, according to the PCC rule, a QoS profile used forthe PC5 interface-based communication of the UE, and sends the QoSprofile to the AMF.

8110. The AMF sends, to the base station, the QoS profile used for thePC5 interface-based communication.

8111. The base station determines that the QoS profile is used for thePC5 interface-based communication, and marks the QoS profile as beingused for the PC5 interface-based communication.

Specifically, for descriptions of steps 8103 to 8106 and 8111, refer tothe related descriptions of the embodiment shown in FIG. 8 a -1 and FIG.8 a -2. Details are not described herein again.

In this embodiment of the present invention, the UE may send, to the SMFthrough the AMF, the PDU session establishment request used to requestthe information used for the PC5 interface-based communication of theUE, so that the SMF can send, to the PCF based on the PDU sessionestablishment request, the request message used to request theinformation used for the PC5 interface-based communication of the UE,and the PCF can send, to the SMF based on the request message, the PCCrule used for the PC5 interface-based communication. Further, afterobtaining the QoS rule and the QoS profile according to the PCC rule,the SMF can send, to the UE through the AMF, the QoS rule used for thePC5 interface-based communication, and send the QoS profile to the basestation through the AMF. In this way, the UE and the base stationdetermine, based on the QoS rule and/or the QoS profile,scheduled-resource information for the UE to perform a V2X service. Thishelps improve reliability and flexibility of the obtained QoSinformation, and prevents the QoS information from being modifiedwithout authorization.

FIG. 9 is a schematic interaction diagram of a communication methodaccording to an embodiment of the present invention. As shown in FIG. 9, the communication method provided in this embodiment of the presentinvention may be based on the system architecture shown in FIG. 7 . Forexample, a first request message is a registration request message. Asshown in FIG. 9 , the method may include the following steps.

901. The UE sends, to the AMF, the registration request message carryingindication information.

The UE may send the registration request message to the AMF through theRAN, to request information for V2X communication. Optionally, theregistration request message may carry the indication information suchas a PC5 indication or a V2X communication indication such as a V2Xcapability indication (where the following uses an example in which theindication information is the V2X capability indication fordescription), to indicate that the registration request message is usedto request the information used for the V2X communication, in otherwords, to indicate that the registration procedure is used to registerUE of a V2X type with a network, in other words, to indicate that theregistration procedure is used to register UE of a V2X type with anetwork and request the information used for the V2X communication. Theinformation for the V2X communication may include information used forPC5 interface-based communication. In other words, the information thatis for the V2X communication and that is requested by using theregistration request message needs to include the information used forthe PC5 interface-based communication.

902. The AMF sends, to the PCF, an access and mobility policy controlcreate (Npcf_AMPolicyControl_Create) message.

After receiving the registration request message, the AMF may send, tothe PCF based on the indication information such as the V2X capabilityindication, a request message, such as the Npcf_AMPolicyControl_Createmessage, that is used to request the information for the PC5interface-based communication. Optionally, theNpcf_AMPolicyControl_Create message may carry the indication informationsuch as the V2X capability indication.

903. The PCF returns, to the AMF, an access and mobility policy controlcreate response (Npcf_AMPolicyControl_Create Response) message thatcarries a QoS rule and/or a QoS profile that are/is used for the PC5interface-based communication.

After receiving the Npcf_AMPolicyControl_Create message, the PCF mayobtain a PCC rule used for the PC5 interface-based communication. Forexample, the PCF may obtain subscription information of the UE (forexample, obtain the subscription information of the UE from the UDR),and further obtain the PCC rule based on the subscription information.Further, the PCF may generate, according to the PCC rule, the QoS ruleand/or the QoS profile that are/is used for the PC5 interface-basedcommunication, and returns the QoS rule and/or the QoS profile to theAMF. For example, the Npcf_AMPolicyControl_Create Response messageincluding the QoS rule and/or the QoS profile may be sent to the AMF.Optionally, the Npcf_AMPolicyControl_Create Response message may includethe information for the V2X communication of the UE, and the informationfor the V2X communication includes the QoS rule and/or the QoS profilethat are/is used for the PC5 interface-based communication.

904. The AMF sends, to the UE, an N1 message carrying the QoS rule.

905. The AMF sends, to the base station, an N2 message carrying the QoSprofile.

Optionally, the AMF may alternatively only send, to the UE, the N1message that carries the QoS rule used for the PC5 interface-basedcommunication. For example, the QoS rule is used only in a scenariowithout network coverage, and the AMF may only send the N1 message tothe UE, but does not send, to the base station, the N2 message thatcarries the QoS profile used for the PC5 interface-based communication.Optionally, the AMF may alternatively only send the N2 message to thebase station. For example, when the UE changes from an idle state to aconnected state, the AMF may only send the N2 message to the basestation, but does not send the N1 message to the UE, because the UEpreviously stores the QoS rule.

Optionally, the N1 message may include a registration accept message, aUE configuration update command message, or the like. The N2 message maybe an initial context setup request message or a UE context modificationrequest.

The AMF may receive the information for the V2X communication that issent by the PCF and that includes the QoS rule and/or the QoS profilethat are/is used for the PC5 interface-based communication; and maysend, to the base station, the QoS profile used for the PC5interface-based communication, and send, to the UE, the QoS rule usedfor the PC5 interface-based communication. For example, theconfiguration update command message including the QoS rule used for thePC5 interface-based communication may be sent to the UE, and the initialcontext setup message including the QoS profile used for the PC5interface-based communication may be sent to the base station. The basestation may receive and store the QoS profile used for the PC5interface-based communication, for example, store the QoS profile incontext information of the UE. The UE may receive and store the QoS ruleused for the PC5 interface-based communication.

Alternatively, in another optional embodiment, the AMF may alternativelyobtain, in another manner, the QoS rule and/or the QoS profile thatare/is used for the PC5 interface-based communication. For example,after the AMF receives the registration request message sent by the UE,the AMF may send a subscription data management getting (service)(Nudm_SDM_Get) message to the UDM to request the subscriptioninformation of the UE. The UDM returns the subscription information tothe AMF. In this way, the AMF obtains the subscription information ofthe UE. The subscription information of the UE may be obtained by theUDM from the UDR. Optionally, the subscription information of the UEincludes the QoS rule and/or the QoS profile. Alternatively, thesubscription information of the UE includes the PCC rule, and then theAMF obtains, based on the subscription information, the QoS rule and/orthe QoS profile that are/is used for the PC5 interface-basedcommunication.

Further, the UE may obtain scheduled-resource information according tothe QoS rule, and send a V2X message on a resource corresponding to thescheduled-resource information. Details are not described herein.

In this embodiment of the present invention, the UE may send, to theAMF, the registration request message used to request the informationused for the PC5 interface-based communication of the UE, so that theAMF can send, to the PCF based on the registration request message, theNpcf_AMPolicyControl_Create message used to request the information usedfor the PC5 interface-based communication of the UE, the PCF can send,to the AMF based on the Npcf_AMPolicyControl_Create message, theinformation for the V2X communication that includes the QoS rule and theQoS profile that are used for the PC5 interface-based communication, andfurther, the AMF can send, to the UE, the QoS rule used for the PC5interface-based communication, and send the QoS profile to the basestation. In this way, QoS information used for the PC5 interface-basedcommunication can be obtained from a network side, so that the UE andthe base station determine, based on the QoS rule and/or the QoSprofile, the scheduled-resource information for the UE to perform a V2Xservice. This helps improve reliability and flexibility of the obtainedQoS information, and prevents the QoS information from being modifiedwithout authorization, thereby reducing improper resource allocation.

The foregoing method embodiments are descriptions of examples of thecommunication method in this application. Each embodiment is describedwith emphasis. For a part that is not described in detail in anembodiment, refer to related descriptions of other embodiments.

FIG. 10 is a possible schematic structural diagram of a communicationsapparatus in the foregoing embodiments. The communications apparatus maybe a core network element such as a mobility management network elementor a session management function network element, may be disposed in acore network element, or may be at least one processing element or chip.Referring to FIG. 10 , the communications apparatus 1000 may include areceiving unit 1001 and a sending unit 1002. These units may performcorresponding functions of the mobility management network element suchas the AMF or the session management function network element such asthe SMF in the foregoing method examples. For example, the receivingunit 1001 is configured to receive a first request message from aterminal, where the first request message is used to request informationused for PC5 interface-based communication of the terminal; and thesending unit 1002 is configured to send, to the terminal based on thefirst request message, a quality of service QoS rule used for the PC5interface-based communication.

Optionally, the sending unit 1002 is further configured to send, to abase station based on the first request message, a QoS profile used forthe PC5 interface-based communication.

Optionally, the apparatus further includes a processing unit 1003.

The sending unit 1002 is further configured to send a second requestmessage to a parameter configuration network element based on the firstrequest message, where the second request message is used to request theinformation used for the PC5 interface-based communication.

The receiving unit 1001 is further configured to receive, from theparameter configuration network element, a policy and charging controlPCC rule used for the PC5 interface-based communication.

The processing unit 1003 is configured to obtain the QoS rule and/or aQoS profile according to the PCC rule.

Optionally, the sending unit 1002 is further configured to send a secondrequest message to a parameter configuration network element based onthe first request message, where the second request message is used torequest the information used for the PC5 interface-based communication.

The receiving unit 1001 is further configured to receive, from theparameter configuration network element, the QoS rule and/or the QoSprofile that are/is used for the PC5 interface-based communication.

Optionally, the first request message includes first indicationinformation. The first indication information is used to indicate thatthe first request message is used to request the information used forthe PC5 interface-based communication.

Optionally, the sending unit 1002 is further configured to send secondindication information to the base station, where the second indicationinformation is used to indicate that the QoS profile is used for the PC5interface-based communication.

Optionally, the first request message is a protocol data unit PDUsession establishment message or a PDU session modification message; andthe apparatus further includes the processing unit 1003, where

the processing unit 1003 is configured to skip triggering establishmentof an N3 tunnel and an N4 tunnel for a PDU session.

It should be understood that, in this embodiment of the presentinvention, division into units is an example, and is merely logicalfunction division. During actual implementation, another division mannermay be used. Functional units in this embodiment of the presentinvention may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units may be integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

Optionally, the communications apparatus may implement, through theforegoing units, some or all of the steps performed by the core networkelement such as the mobility management network element or the sessionmanagement function network element in the communication methods in theembodiments shown in FIG. 2 a to FIG. 9 . It should be understood thatthis embodiment of the present invention is an apparatus embodimentcorresponding to the method embodiment, and the descriptions of themethod embodiment are also applicable to this embodiment of the presentinvention.

Referring to FIG. 11 , in another embodiment, a communications apparatus1100 may include a processor 1101 and a transceiver 1102. Optionally,the communications apparatus may further include a memory 1103. Theprocessor 1101, the transceiver 1102, and the memory 1103 may beconnected to each other. For example, the processor 1101, thetransceiver 1102, and the memory 1103 may be connected to each other viaa bus 1104. The bus 1104 may be a peripheral component interconnect (PCIfor short) bus, an extended industry standard architecture (EISA forshort) bus, or the like. The bus may be classified into an address bus,a data bus, a control bus, and the like. For ease of representation,only one thick line is used to represent the bus in FIG. 11 , but thisdoes not mean that there is only one bus or only one type of bus.

The processor 1101 may be a processor or a controller, for example, maybe a central processing unit (CPU for short), a general purposeprocessor, a digital signal processor (DSP for short), anapplication-specific integrated circuit (ASIC for short), a fieldprogrammable gate array (FPGA for short) or another programmable logicdevice, a transistor logic device, a hardware component, or anycombination thereof. The processor 1101 may implement or execute variousexamples of logical blocks, modules, and circuits described withreference to content disclosed in this application. Alternatively, theprocessor may be a combination of processors implementing a computingfunction, for example, a combination of one or more microprocessors, ora combination of the DSP and a microprocessor. The transceiver 1102 mayinclude an independent receiver and an independent transmitter, or maybe obtained by integrating the receiver and the transmitter.

The processor 1101 is configured to control and manage an action of thecommunications apparatus such as a core network element. For example,the processor 1101 is configured to support the communications apparatusin performing the step 304 in FIG. 3 , the step 403 in FIG. 4 , the step802 in FIG. 8 a -1, and/or another step used for the technologydescribed in this specification. The transceiver 1102 may perform acommunication function, and is configured to support the communicationsapparatus in communicating with another network entity such as aparameter configuration network element, a base station, or a terminal,for example, communicating with the functional unit or the networkentity shown in FIG. 2 a to FIG. 9 , to perform, for example, the steps201 and 202 in FIG. 2 a , the steps 301 to 303, 305, and 306 in FIG. 3 ,the steps 402, 404, and 405 in FIG. 4 , the steps 501 to 505 in FIG. 5 ,the steps 602 to 604 in FIG. 6 , the steps 801, 803, and 805 to 807 inFIG. 8 a -1 and FIG. 8 a -2, the steps 901 to 905 in FIG. 9 , and/oranother step used for the technology described in this specification.Specifically, the processor 1101 is configured to determine to send orreceive a signal, and is a controller of the communication function. Tobe specific, when sending or receiving a signal, the processor 1101controls or drives the transceiver 1102 to perform related sending orreceiving. The transceiver 1102 may implement a specific communicationoperation under control of the processor 1101, and is an executor of thecommunication function.

Further, the memory 1103 may be configured to store at least one ofprogram code and data of the communications apparatus. When theprocessor 1101 works under driving of software such as a CPU, a DSP, ora microcontroller, the processor 1101 may read the program code storedin the memory 1103 and work under driving of the program code.

Method or algorithm steps described in combination with the contentdisclosed in the present invention may be implemented by hardware, ormay be implemented by a processor by executing a software instruction.The software instruction may include a corresponding software module.The software module may be stored in a random access memory (RAM forshort), a flash memory, a read-only memory (ROM for short), an erasableprogrammable read-only memory (EPROM for short), an electricallyerasable programmable read-only memory (electrically EPROM, EEPROM forshort), a register, a hard disk, a removable hard disk, a compact discread-only memory (CD-ROM), or any other form of storage mediumwell-known in the art. For example, a storage medium is coupled to aprocessor, so that the processor can read information from the storagemedium and write information into the storage medium. Certainly, thestorage medium may alternatively be a component of the processor. Theprocessor and the storage medium may be located in the ASIC. Inaddition, the ASIC may be located in the communications apparatus.Certainly, the processor and the storage medium may alternatively existin the communications apparatus as discrete components.

FIG. 12 is a possible schematic structural diagram of a communicationsapparatus in the foregoing embodiments. The communications apparatus maybe a parameter configuration network element, may be disposed in aparameter configuration network element, or may be at least oneprocessing element or chip. Referring to FIG. 12 , the communicationsapparatus 1200 may include a receiving unit 1201 and a sending unit1202. These units may perform corresponding functions of the parameterconfiguration network element such as the PCF in the foregoing methodexamples. For example, the receiving unit 1201 is configured to receivea request message from a core network element, where the request messageis used to request information used for PC5 interface-basedcommunication of a terminal; and the sending unit 1202 is configured tosend, to the core network element based on the request message, a policyand charging control PCC rule used for the PC5 interface-basedcommunication; or the sending unit 1202 is configured to send, to thecore network element based on the request message, a quality of serviceQoS rule and/or a QoS profile that are/is used for the PC5interface-based communication.

Optionally, the communications apparatus is a policy and chargingfunction PCF network element, and the request message is an access andmobility policy control create (Npcf_AMPolicyControl_Create) message.Alternatively, the communications apparatus is a vehicle-to-everythingV2X parameter configuration network element, and the request message isa V2X parameter request message.

Optionally, the request message includes indication information. Theindication information is used to indicate that the request message isused to request the information used for the PC5 interface-basedcommunication.

It should be understood that, in this embodiment of the presentinvention, division into units is an example, and is merely logicalfunction division. During actual implementation, another division mannermay be used. Functional units in this embodiment of the presentinvention may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units may be integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

Optionally, the communications apparatus may implement, through theforegoing units, some or all of the steps performed by the parameterconfiguration network element in the communication methods in theembodiments shown in FIG. 2 a to FIG. 9 . It should be understood thatthis embodiment of the present invention is an apparatus embodimentcorresponding to the method embodiment, and the descriptions of themethod embodiment are also applicable to this embodiment of the presentinvention.

Referring to FIG. 13 , in another embodiment, a communications apparatus1300 such as a parameter configuration network element may include aprocessor 1301 and a transceiver 1302. Optionally, the communicationsapparatus may further include a memory 1303. The processor 1301, thetransceiver 1302, and the memory 1303 may be connected to each other.For example, the processor 1301, the transceiver 1302, and the memory1303 may be connected to each other via a bus 1304. The bus 1304 may bea PCI bus, an EISA bus, or the like. The bus may be classified into anaddress bus, a data bus, a control bus, and the like. For ease ofrepresentation, only one thick line is used to represent the bus in FIG.13 , but this does not mean that there is only one bus or only one typeof bus.

The processor 1301 may be a processor or a controller, for example, maybe a CPU, a general purpose processor, a DSP, an ASIC, an FPGA oranother programmable logic device, a transistor logic device, a hardwarecomponent, or any combination thereof. The processor 1301 may implementor execute various examples of logical blocks, modules, and circuitsdescribed with reference to content disclosed in this application.Alternatively, the processor may be a combination of processorsimplementing a computing function, for example, a combination of one ormore microprocessors, or a combination of the DSP and a microprocessor.The transceiver 1302 may include an independent receiver and anindependent transmitter, or may be obtained by integrating the receiverand the transmitter.

The processor 1301 is configured to control and manage an action of thecommunications apparatus. For example, the processor 1301 is configuredto support the communications apparatus in performing the step 401 inFIG. 4 , the step 601 in FIG. 6 , the step 804 in FIG. 8 a -1, and/oranother step used for the technology described in this specification.The transceiver 1302 may perform a communication function, and isconfigured to support the communications apparatus in communicating withanother network entity such as a core network element, for example,communicating with the functional unit or the network entity shown inFIG. 2 a to FIG. 9 , to perform, for example, the steps 302 and 303 inFIG. 3 , the step 402 in FIG. 4 , the steps 502 and 503 in FIG. 5 , thestep 602 in FIG. 6 , the steps 803 and 805 in FIG. 8 a -1, the steps 902and 903 in FIG. 9 , and/or another step used for the technologydescribed in this specification. Specifically, the processor 1301 isconfigured to determine to send or receive a signal, and is a controllerof the communication function. To be specific, when sending or receivinga signal, the processor 1301 controls or drives the transceiver 1302 toperform related sending or receiving. The transceiver 1302 may implementa specific communication operation under control of the processor 1301,and is an executor of the communication function.

Further, the memory 1303 may be configured to store at least one ofprogram code and data of the communications apparatus. When theprocessor 1301 works under driving of software such as a CPU, a DSP, ora microcontroller, the processor 1301 may read the program code storedin the memory 1303 and work under driving of the program code.

Method or algorithm steps described in combination with the contentdisclosed in the present invention may be implemented by hardware, ormay be implemented by a processor by executing a software instruction.The software instruction may include a corresponding software module.The software module may be stored in a random access memory (RAM), aflash memory, a read-only memory (ROM), an erasable programmableread-only memory (EPROM), an electrically erasable programmableread-only memory (EEPROM), a register, a hard disk, a removable harddisk, a compact disc read-only memory (CD-ROM), or any other form ofstorage medium well-known in the art. For example, a storage medium iscoupled to a processor, so that the processor can read information fromthe storage medium and write information into the storage medium.Certainly, the storage medium may alternatively be a component of theprocessor. The processor and the storage medium may be located in theASIC. In addition, the ASIC may be located in the communicationsapparatus. Certainly, the processor and the storage medium mayalternatively exist in the communications apparatus as discretecomponents.

FIG. 14 is still another possible schematic structural diagram of acommunications apparatus in the foregoing embodiments. Thecommunications apparatus may be a base station, may be disposed in abase station, or may be at least one processing element or chip.Referring to FIG. 14 , the communications apparatus 1400 may include areceiving unit 1401 and a sending unit 1402. These units may performcorresponding functions of the base station in the foregoing methodexamples. For example, the receiving unit 1401 is configured to receivea request message from a terminal, where the request message is used torequest information used for PC5 interface-based communication of theterminal; the sending unit 1402 is configured to send the requestmessage to a core network element; the receiving unit 1401 is furtherconfigured to receive, from the core network element, a quality ofservice QoS rule used for the PC5 interface-based communication; and thesending unit 1402 is further configured to send the QoS rule to theterminal.

Optionally, the receiving unit 1401 is further configured to receive,from the core network element, a QoS profile used for the PC5interface-based communication.

Optionally, the receiving unit 1401 is further configured to receiveindication information from the core network element, where theindication information is used to indicate that the QoS profile is usedfor the PC5 interface-based communication.

Optionally, the request message is a protocol data unit PDU sessionestablishment message or a PDU session modification message; and theapparatus further includes a processing unit 1403, where

the processing unit 1403 is configured to skip triggering establishmentof an air-interface data radio bearer (DRB) and/or an N3 tunnel for aPDU session.

Optionally, the receiving unit 1401 is further configured to receive ascheduling request from the terminal, where the scheduling requestincludes an identifier of the QoS rule; and

the sending unit 1402 is further configured to send scheduled-resourceinformation to the terminal based on the identifier of the QoS rule.

It should be understood that, in this embodiment of the presentinvention, division into units is an example, and is merely logicalfunction division. During actual implementation, another division mannermay be used. Functional units in this embodiment of the presentinvention may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units may be integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

Optionally, the communications apparatus may implement, through theforegoing units, some or all of the steps performed by the base stationin the communication methods in the embodiments shown in FIG. 2 a toFIG. 9 . It should be understood that this embodiment of the presentinvention is an apparatus embodiment corresponding to the methodembodiment, and the descriptions of the method embodiment are alsoapplicable to this embodiment of the present invention.

Referring to FIG. 15 , in another embodiment, the communicationsapparatus 1500 such as a base station may include a processor 1501 and atransceiver 1502. Optionally, the communications apparatus may furtherinclude a memory 1503. The processor 1501, the transceiver 1502, and thememory 1503 may be connected to each other. For example, the processor1501, the transceiver 1502, and the memory 1503 may be connected to eachother via a bus 1504. The bus 1504 may be a PCI bus, an EISA bus, or thelike. The bus may be classified into an address bus, a data bus, acontrol bus, and the like. For ease of representation, only one thickline is used to represent the bus in FIG. 15 , but this does not meanthat there is only one bus or only one type of bus.

The processor 1501 may be a processor or a controller, for example, maybe a CPU, a general purpose processor, a DSP, an ASIC, an FPGA oranother programmable logic device, a transistor logic device, a hardwarecomponent, or any combination thereof. The processor 1501 may implementor execute various examples of logical blocks, modules, and circuitsdescribed with reference to content disclosed in this application.Alternatively, the processor may be a combination of processorsimplementing a computing function, for example, a combination of one ormore microprocessors, or a combination of the DSP and a microprocessor.The transceiver 1502 may include an independent receiver and anindependent transmitter, or may be obtained by integrating the receiverand the transmitter.

The processor 1501 is configured to control and manage an action of thecommunications apparatus. For example, the processor 1501 is configuredto support the communications apparatus in performing the process 808 inFIG. 8 a -2 and/or another process used for the technology described inthis specification. The transceiver 1502 may perform a communicationfunction, and is configured to support the communications apparatus incommunicating with another network entity such as a terminal or corenetwork element, for example, communicating with the functional unit orthe network entity shown in FIG. 2 a to FIG. 9 , to perform, forexample, the steps 2101 to 2103 in FIG. 2 b , the step 306 in FIG. 3 ,the step 405 in FIG. 4 , the step 505 in FIG. 5 , the step 604 in FIG. 6, the step 807 in FIG. 8 a -2, the step 905 in FIG. 9 , and/or anotherstep used for the technology described in this specification.Specifically, the processor 1501 is configured to determine to send orreceive a signal, and is a controller of the communication function. Tobe specific, when sending or receiving a signal, the processor 1501controls or drives the transceiver 1502 to perform related sending orreceiving. The transceiver 1502 may implement a specific communicationoperation under control of the processor 1501, and is an executor of thecommunication function.

Further, the memory 1503 may be configured to store at least one ofprogram code and data of the communications apparatus. When theprocessor 1501 works under driving of software such as a CPU, a DSP, ora microcontroller, the processor 1501 may read the program code storedin the memory 1503 and work under driving of the program code.

Method or algorithm steps described in combination with the contentdisclosed in the present invention may be implemented by hardware, ormay be implemented by a processor by executing a software instruction.The software instruction may include a corresponding software module.The software module may be stored in a random access memory (RAM), aflash memory, a read-only memory (ROM), an erasable programmableread-only memory (EPROM), an electrically erasable programmableread-only memory (EEPROM), a register, a hard disk, a removable harddisk, a compact disc read-only memory (CD-ROM), or any other form ofstorage medium well-known in the art. For example, a storage medium iscoupled to a processor, so that the processor can read information fromthe storage medium and write information into the storage medium.Certainly, the storage medium may alternatively be a component of theprocessor. The processor and the storage medium may be located in theASIC. In addition, the ASIC may be located in the communicationsapparatus. Certainly, the processor and the storage medium mayalternatively exist in the communications apparatus as discretecomponents.

FIG. 16 is still another possible schematic structural diagram of acommunications apparatus in the foregoing embodiments. Thecommunications apparatus may be a terminal, may be disposed in aterminal, or may be at least one processing element or chip. Referringto FIG. 16 , the communications apparatus 1600 may include a sendingunit 1601 and a receiving unit 1602. These units may performcorresponding functions of the terminal such as the UE in the foregoingmethod examples. For example, the sending unit 1601 is configured tosend a request message to a core network element, where the requestmessage is used to request information used for PC5 interface-basedcommunication of the terminal; and the receiving unit 1602 is configuredto receive, from the core network element, a quality of service QoS ruleused for the PC5 interface-based communication.

Optionally, the request message includes indication information. Theindication information is used to indicate that the request message isused to request the information used for the PC5 interface-basedcommunication.

Optionally, the sending unit 1601 is further configured to send ascheduling request to a base station, where the scheduling requestincludes an identifier of the QoS rule; and

the receiving unit 1602 is further configured to: receivescheduled-resource information from the base station, and send avehicle-to-everything V2X message on a resource corresponding to thescheduled-resource information.

It should be understood that, in this embodiment of the presentinvention, division into units is an example, and is merely logicalfunction division. During actual implementation, another division mannermay be used. Functional units in this embodiment of the presentinvention may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units may be integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

Optionally, the communications apparatus may implement, through theforegoing units, some or all of the steps performed by the terminal inthe communication methods in the embodiments shown in FIG. 2 a to FIG. 9. It should be understood that this embodiment of the present inventionis an apparatus embodiment corresponding to the method embodiment, andthe descriptions of the method embodiment are also applicable to thisembodiment of the present invention.

Referring to FIG. 17 , in another embodiment, the communicationsapparatus 1700 such as a terminal may include a processor 1701 and atransceiver 1702. Optionally, the communications apparatus may furtherinclude a memory 1703. The processor 1701, the transceiver 1702, and thememory 1703 may be connected to each other. For example, the processor1701, the transceiver 1702, and the memory 1703 may be connected to eachother via a bus 1704. The bus 1704 may be a PCI bus, an EISA bus, or thelike. The bus may be classified into an address bus, a data bus, acontrol bus, and the like. For ease of representation, only one thickline is used to represent the bus in FIG. 17 , but this does not meanthat there is only one bus or only one type of bus.

The processor 1701 may be a processor or a controller, for example, maybe a CPU, a general purpose processor, a DSP, an ASIC, an FPGA oranother programmable logic device, a transistor logic device, a hardwarecomponent, or any combination thereof. The processor 1701 may implementor execute various examples of logical blocks, modules, and circuitsdescribed with reference to content disclosed in this application.Alternatively, the processor may be a combination of processorsimplementing a computing function, for example, a combination of one ormore microprocessors, or a combination of the DSP and a microprocessor.The transceiver 1702 may include an independent receiver and anindependent transmitter, or may be obtained by integrating the receiverand the transmitter.

The processor 1701 is configured to control and manage an action of thecommunications apparatus. For example, the processor 1701 is configuredto support the communications apparatus in performing the step 203 inFIG. 2 a , the step 307 in FIG. 3 , the step 506 in FIG. 5 , and/oranother step used for the technology described in this specification.The transceiver 1702 may perform a communication function, and isconfigured to support the communications apparatus in communicating withanother network entity such as a base station or a core network element,for example, communicating with the functional unit or the networkentity shown in FIG. 2 a to FIG. 9 , to perform, for example, the steps201 and 202 in FIG. 2 a , the steps 301 and 305 in FIG. 3 , the step 404in FIG. 4 , the steps 501 and 504 in FIG. 5 , the step 603 in FIG. 6 ,the steps 801 and 806 in FIG. 8 a -1 and FIG. 8 a -2, the steps 901 and904 in FIG. 9 , and/or another step used for the technology described inthis specification. Specifically, the processor 1701 is configured todetermine to send or receive a signal, and is a controller of thecommunication function. To be specific, when sending or receiving asignal, the processor 1701 controls or drives the transceiver 1702 toperform related sending or receiving. The transceiver 1702 may implementa specific communication operation under control of the processor 1701,and is an executor of the communication function.

Further, the memory 1703 may be configured to store at least one ofprogram code and data of the communications apparatus. When theprocessor 1701 works under driving of software such as a CPU, a DSP, ora microcontroller, the processor 1701 may read the program code storedin the memory 1703 and work under driving of the program code.

Method or algorithm steps described in combination with the contentdisclosed in the present invention may be implemented by hardware, ormay be implemented by a processor by executing a software instruction.The software instruction may include a corresponding software module.The software module may be stored in a random access memory (RAM), aflash memory, a read-only memory (ROM), an erasable programmableread-only memory (EPROM), an electrically erasable programmableread-only memory (EEPROM), a register, a hard disk, a removable harddisk, a compact disc read-only memory (CD-ROM), or any other form ofstorage medium well-known in the art. For example, a storage medium iscoupled to a processor, so that the processor can read information fromthe storage medium and write information into the storage medium.Certainly, the storage medium may alternatively be a component of theprocessor. The processor and the storage medium may be located in theASIC. In addition, the ASIC may be located in the communicationsapparatus. Certainly, the processor and the storage medium mayalternatively exist in the communications apparatus as discretecomponents.

This application further provides a communications system. The systemincludes the foregoing core network element, parameter configurationnetwork element, base station, and/or terminal. Optionally, the systemmay further include another device that interacts with the foregoingnetwork elements in the solutions provided in the embodiments of thepresent invention. The core network element, the parameter configurationnetwork element, the base station, and/or the terminal may perform someor all of the steps in the communication methods in the embodimentsshown in FIG. 2 a to FIG. 9 . For details, refer to the relateddescriptions of the foregoing embodiments, and the details are notdescribed herein again.

In an implementation process, the steps in the foregoing methods can beimplemented through a hardware integrated logical circuit in theprocessor, or by using instructions in a form of software. The steps ofthe methods disclosed with reference to the embodiments of thisapplication may be directly performed by a hardware processor, or may beperformed by using a combination of hardware in the processor and asoftware module. The software module may be located in a mature storagemedium in the art, such as a random access memory, a flash memory, aread-only memory, a programmable read-only memory, an electricallyerasable programmable memory, or a register. The storage medium islocated in the memory, and the processor reads information in the memoryand completes the steps in the foregoing methods in combination withhardware of the processor. To avoid repetition, details are notdescribed herein again.

It should further be understood that the “first”, “second”, “third” andvarious digital numbers in this specification are merely fordifferentiation for ease of description, and are not intended to limitthe scope of the embodiments of the present invention.

It should be understood that the term “and/or” in this specificationdescribes only an association relationship for describing associatedobjects and represents that three relationships may exist. For example,A and/or B may represent the following three cases: Only A exists, bothA and B exist, and only B exists. In addition, the character “I” in thisspecification generally indicates an “or” relationship between theassociated objects.

It should be understood that sequence numbers of the foregoing steps donot mean execution sequences in various embodiments of this application.The execution sequences of the steps should be determined according tofunctions and internal logic of the steps, and should not be construedas any limitation on the implementation steps of the embodiments of thepresent invention.

A person of ordinary skill in the art may be aware that, in combinationwith various illustrative logical blocks and steps described in theembodiments disclosed in this specification may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraints of thetechnical solutions. A person skilled in the art may use a differentmethod to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of this application.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, refer to acorresponding process in the foregoing method embodiments, and detailsare not described herein again.

All or some of the foregoing embodiments may be implemented by usingsoftware, hardware, firmware, or any combination thereof. When softwareis used to implement the embodiments, the embodiments may be implementedcompletely or partially in a form of a computer program product. Thecomputer program product includes one or more computer instructions.When the computer program instructions are loaded and executed on acomputer, the procedures or functions according to the embodiments ofthe present invention are all or partially generated. The computer maybe a general-purpose computer, a special-purpose computer, a computernetwork, or other programmable apparatuses. The computer instructionsmay be stored in a computer-readable storage medium or may betransmitted from a computer-readable storage medium to anothercomputer-readable storage medium. For example, the computer instructionsmay be transmitted from a website, computer, server, or data center toanother website, computer, server, or data center in a wired (forexample, a coaxial cable, an optical fiber, or a digital subscriber line(DSL)) or wireless (for example, infrared, radio, or microwave) manner.The computer-readable storage medium may be any usable medium accessibleto the computer, or a data storage device, such as a server or a datacenter, integrating one or more usable media. The usable medium may be amagnetic medium (for example, a soft disk, a hard disk, or a magnetictape), an optical medium (for example, a DVD), a semiconductor medium(for example, a solid-state drive Solid State Disk (SSD)), or the like.

1. A communication apparatus, comprising: at least one processor; andone or more memories coupled to the at least one processor and storingprogramming instructions for execution by the at least one processor to:receive a first request message from a terminal, wherein the firstrequest message is used to request information used for PC5interface-based communication of the terminal; send a second requestmessage to a policy and charging function network element based on thefirst request message, wherein the second request message is used torequest the information used for the PC5 interface-based communication;receive, from the policy and charging function network element, aquality of service (QoS) rule used for the PC5 interface-basedcommunication; and send, to the terminal and based on the first requestmessage, the QoS rule, wherein the apparatus is a mobility managementnetwork element or located in a mobility management network element. 2.The apparatus according to claim 1, wherein the programming instructionsare for execution by the at least one processor to: send, to a basestation and based on the first request message, a QoS profile used forthe PC5 interface-based communication.
 3. The apparatus according toclaim 2, wherein the programming instructions are for execution by theat least one processor to: send first indication information to the basestation, wherein the first indication information is used to indicatethat the QoS profile is used for the PC5 interface-based communication.4. The apparatus according to claim 1, wherein the first request messagecomprises second indication information, and wherein the secondindication information is used to indicate that the first requestmessage is used to request the information used for the PC5interface-based communication.
 5. The apparatus according to claim 1,wherein the first request message is a protocol data unit (PDU) sessionestablishment message or a PDU session modification message, and whereinthe programming instructions are for execution by the at least oneprocessor to: skip triggering establishment of an N3 tunnel and an N4tunnel for a PDU session.
 6. A non-transitory computer-readable mediumstoring computer instructions, that when executed by one or moreprocessors, cause the one or more processors to perform operationscomprising: receiving a first request message from a terminal, whereinthe first request message is used to request information used for PC5interface-based communication of the terminal; sending a second requestmessage to a policy and charging function network element based on thefirst request message, wherein the second request message is used torequest the information used for the PC5 interface-based communication;receiving, from the policy and charging function network element, aquality of service (QoS) rule used for the PC5 interface-basedcommunication; and sending, to the terminal and based on the firstrequest message, the QoS rule.
 7. The non-transitory computer-readablemedium according to claim 6, wherein the operations comprise: sending,to a base station and based on the first request message, a QoS profileused for the PC5 interface-based communication.
 8. The non-transitorycomputer-readable medium according to claim 7, wherein the operationscomprise: sending first indication information to the base station,wherein the first indication information is used to indicate that theQoS profile is used for the PC5 interface-based communication.
 9. Thenon-transitory computer-readable medium according to claim 6, whereinthe first request message comprises second indication information, andwherein the second indication information is used to indicate that thefirst request message is used to request the information used for thePC5 interface-based communication.
 10. The non-transitorycomputer-readable medium according to claim 6, wherein the first requestmessage is a protocol data unit (PDU) session establishment message or aPDU session modification message, and wherein the operations comprise:skipping triggering establishment of an N3 tunnel and an N4 tunnel for aPDU session.
 11. A communication system, comprising a terminal, amobility management network element, and a policy and charging functionnetwork element, wherein: the terminal is configured to send a firstrequest message to the mobility management network element, wherein thefirst request message is used to request information used for PC5interface-based communication of the terminal; the mobility managementnetwork element is configured to receive the first request message, andsend a second request message to the policy and charging functionnetwork element based on the first request message, wherein the secondrequest message is used to request the information used for the PC5interface-based communication; the policy and charging function networkelement is configured to send a quality of service (QoS) rule used forthe PC5 interface-based communication to the mobility management networkelement; and the mobility management network element is furtherconfigured to receive the QoS rule, and send, based on the first requestmessage, the QoS rule to the terminal.
 12. The system according to claim11, wherein the mobility management network element is furtherconfigured to: send, to a base station and based on the first requestmessage, a QoS profile used for the PC5 interface-based communication.13. The system according to claim 12, wherein the mobility managementnetwork element is further configured to: send first indicationinformation to the base station, wherein the first indicationinformation is used to indicate that the QoS profile is used for the PC5interface-based communication.
 14. The system according to claim 11,wherein the first request message comprises second indicationinformation, and wherein the second indication information is used toindicate that the first request message is used to request theinformation used for the PC5 interface-based communication.
 15. Thesystem according to claim 11, wherein the first request message is aprotocol data unit (PDU) session establishment message or a PDU sessionmodification message, and wherein the mobility management networkelement is further configured to: skip triggering establishment of an N3tunnel and an N4 tunnel for a PDU session.